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AUGUST 1980 Volume 5; Number 8 , $2.50 in USA/$2.95 in. Canada 





s 




the small systems jour i 





LIE 





THE FORTH L 



OFTEN FIRST - ALWAYS THE BEST 

When we introduced the "S" system last year we knew that we were ahead of the industry. 
We didn't realize just how far. 



WE KNEW THE NEEDS- 

When we began designing the S/09 computer, we 
knew that the normal eight-bit microprocessor sys- 
tem was not adequate for any but the smallest, 
single user business applications. What was worse 
there was little that could be done to expand the 
capabilities of the system if the customer needed 
it. There is nothing much worse to a business 
customer than a "dead end" system. 

MEMORY IS THE KEY- 

Obviously a business system should be able to 
operate with multiple terminals if needed. It 
should also be able to do a variety of jobs; not just 
data processing, but also word processing and com- 
puter aided instruction. With a system limited to 
64K bytes of memory addresses such a system is 
just not practical. The amount of user memory 
available to each terminal is too small for useful 
work. 

HOW DO YOU GET IT- 

The common solution to this problem is called 
bank switching. This process is similar to a selector 
switch that turns on the bank of memory that you 
want to work with. This, however, has a few pro- 
blems. It is inefficient, therefore expensive, plus 
being slow. It is also extremely clumsy when data 
must be exchanged between two different pro- 
grams. Besides with all this you still cannot use 
more than 64K of memory for any one program. 
So what is the alternative? 

DO ITRIGHT- 

The alternative is an address bus with more than 
the normal 16 bits found on eight-bit microproces- 
sors. By using 20 address bits you can, for instance, 
address up to a million memory locations directly. 

This way you have access to any part of memory at 
any time without any intermediate processes. Pro- 
gram interaction is now no problem at all. 

SOFTWARE MUST MATCH- 

So far we have a computer system with a large 
memory capacity and the ability to operate with 
many terminals, but this is not enough. You need 
an operating system just as sophisticated as the 



hardware to complete the job. It must be a multi- 
tasking (therefore multiuser) operating system and 
it must be fast if it is to be useful with multiter- 
minal systems. UniFLEX® fills these requirements 
and more. It also has multiple directories, log-in 
and password features. UniFLEX® was patterned 
after UNIX™-,which is one of the most highly re- 
garded operating systems around. 

PERIPHERALS TOO- 

To complete the system we offer our smart ter- 
minals, and a variety of disk systems. We have 
everthing from a 390K byte floppy to a 40 Meg/ 
byte Winchester drive. All peripherals are compa- 
tible and so you can start with a small single 
terminal system and upgrade if necessary to a fully 
expanded system— 16 terminals, 768 bytes of RAM 
memory and 96 Meg/bytes of disk storage. 

GET THE WHOLE STORY- 

If you are planning to install, or sell business 
systems you should get our information package 
on the most versatile and cost effective system on 
the market, the S/09. You can get a 128K system 
(less printer) for a little over $5,000.00. 

*UNIX is a Trademark of Bell Laboratories. 



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Along with the SDI we also offer an 
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CONTACT YOUR REP NOW 

The Model SDI has been used in scien- 
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good example of how Cromemco keeps 
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turns any Cromemco computer into an 
up-to-date color display computer. 

The SDI has still more features that 
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BYTE August 1980 




Here's the state of the art 
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OF 

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Yes, the Cromemco Model Z-2H 
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These Z-2H features tell you why: 

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This expandability is supported by 
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LOW COST — SEE IT NOW 

The Z-2H is real. It's been in the 
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You should see the Z-2H now. Con- 
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Cromemco 

Incorporated 
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Tomorrow's computers today 



(415)964-7400 



m 



In The Oueue 



EITE August 1980 
Volume 5, Number 8 




Page 22 




Page 58 




Page 164 




Foreground 

22 A BUILD-IT-YOURSELF MODEM FOR UNDER $50 

by Steve Ciarcia 

This originate-only modem will allow you to get started in intercomputer communica- 
tion with minimal expense. 

58 THE HARD-DISK EXPLOSION: HIGH-POWERED MASS 
STORAGE FOR YOUR PERSONAL COMPUTER 

by Tom Manuel 

Thanks to new hard-disk technology, personal computer users can add millions of bytes 
of mass storage to their systems at a reasonable cost. 

100 WHAT IS FORTH? A TUTORIAL INTRODUCTION 

by John S James 

Here is an overview of FORTH that lays the foundation for the other theme articles in 
this BYTE. 

150 BREAKFORTH INTO FORTH by A Richard Miller 
and Jill Miller 

If you can't imagine any personal use for FORTH, can you imagine a 96-line program 
that plays a fast, animated game with sound on the TRS-80? 

164 FORTH EXTENSIBILITY: OR HOW TO WRITE A COM- 
PILER IN TWENTY-FIVE WORDS OR LESS by Kim Harris 

This tutorial explains the capability for defining new families of FORTH words. 

210 CONSTRUCTION OF A FOURTH-GENERATION VIDEO 
TERMINAL, PART 1 by Theron Wierenga 

Part 1 of this article presents a new design using the 8275 controller and a dedicated 
Z80 microprocessor. 



Background 



76 THE EVOLUTION OF FORTH, AN UNUSUAL 
LANGUAGE by Charles H Moore 

The inventor of the language recalls its design and how it evolved over a 10-year 
period. 

198 KHACHIYAN'S ALGORITHM, PART 1: A NEW SOLU- 
TION TO LINEAR PROGRAMMING PROBLEMS 

by G C Berresford, A M Rockett, and J C Stevenson 

Now you can study the algorithm that promised to revolutionize linear programming. 

Nucleus 



Page 210 



6 


Editorial: Threads of a FORTH 


94 


BYTELINES 




Tapestry 


98 


Selected FORTH Vendors 


14 


Letters 


196 


A FORTH Glossary 


40 


Product Review: The Ohio Scien- 


226 


Clubs and Newsletters 




tific CA-15 Universal Telephone In- 


230 


Event Queue 




terface 


234 


Ask BYTE 


46 


Product Review: The Heath H-89 


248 


What's New? 




Computer 


302 


Unclassified Ads 


72 


Programming Quickies: Self- 


303 


BOMB, BOMB Results 




Reproducing Programs 


304 


Reader Service 



August 1980 © BYTE Publications Inc 



Publishers 

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Associate Publisher 
John E Hayes 
Assistant 
Cheryl A Hurd 

Editorial Director 

Carl T Helmers Jr 

Editor-in-Chief 

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Richard S Shuford, Gregg Williams, 

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Consulting Editor 

Mark Dahmke 

Book Editor 

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Chiet Copy Editor 

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Copy Editors 

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Robin M Moss, Anthony J Lockwood 

Assistant to the Editors 

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Assistants 

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New Products Editor 

Clubs, Newsletters 

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Drafting 

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Production Director 

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Assistant Production Director 

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Production/Advertising Coordinator 

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ON THE COVER 

This month's cover by Robert Tinney shows a rocket-like needle 
threading its way through granite cubes labeled: 
DOUBLE , DUPLICATE , and + . The threaded path of the 
needle is a representation of the process used in FORTH and other 
threaded languages to create a new word (here, DOUBLE ) with 


previously defined words (here, DUPLICATE and + ). 

Other aspects of this fascinating language are described in the 
editorial, "Threads of a FORTH Tapestry," and in the theme 
articles for this issue. 



Officers of McGraw-Hill Publications Company: Paul F. McPherson, President; Executive Vice Presidents: James 
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August 1980 © BYTE Publications Inc 



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Editorial 



Threads of a FORTH Tapestry 



Editor's Note: This month's editorial is by BYTE Editor Gregg Williams. 
Gregg was responsible for the preparation of this month's special section 
devoted to the FORTH language. Carl Helmers returns next month with 
an editorial CM 



What do a portable heart monitor, the new Craig Language 
Translator, a peach-sorting machine, and a movie called Battle 
Beyond the Stars have in common? The answer is FORTH, a not-so-new 
language as comfortable in industrial machinery as it is in a personal com- 
puter. In fact, it was originally used by its inventor, Charles H Moore, to con- 
trol the telescope and equipment at the Kitt Peak Observatory. 

Although I have known about FORTH for about a year, it was only during 
the preparation of this issue that I began to actively keep my ears open for 
mention of this unusual language. I have uncovered a lot of information (and 
some experience) about FORTH and its variations. The language is so unusual 
that no single line of thought could give you a picture of what the language is 
like. Instead, the following sections represent several threads from the rich 
tapestry called FORTH. 

FORTH in the Real World 

No language I know of is as comfortable in real-world situations as FORTH. 
Here are some examples of the breadth of applications that have been created 
using FORTH: 

• Elicon Inc of Brea, California, is using FORTH software to drive the 
same kind of computer-controlled cameras that were used to film the 
sophisticated space-battle scenes in Star Wars. New World Productions of 
Venice, California, is using this camera system to film the spaceship sequences 
in the motion picture Battle Beyond the Stars. In a related development, 
Magicam Inc (which devised a number of the special effects for the recent 
movie Star Trek) is in the process of converting control of its master-slave 
camera pair from an analog computer to a digital computer running FORTH 
software. In the Magicam process, the master camera follows actors on a 
special blue stage while the computer guides the slave camera across a detailed 
model. Later, the two images are optically combined, producing the effect of 
the actors actually being in the landscape depicted on the model. 

• Allen Test Products of Kalamazoo, Michigan, has developed an igni- 
tion analyzer for use in service stations and automobile repair shops that 
analyzes the behavior of automobile ignition systems and displays both 
diagnostic and corrective information. Formerly, the voltage waveform from a 
spark plug was displayed on an oscilloscope, after which a mechanic would 
attempt repairs based on his interpretation of the waveforms. 

• Atari Inc is using FORTH in two of its divisions and is rumored to be 
contemplating other uses for the language. In its Coin-Operated Division, 



6 August 1980 © BYTE Publications Inc 




"For reliable data storage, 
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MM -m wm ■m J»M #fc|%»%«j"" M Raymond Schlitzcr, Owner— 

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"I sell systems my customers can depend 
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small business computer systems sold here 
feature Minifloppy disk drives. I know 
from experience I can rely on the 
Minifloppy?' 

Since 1976 Shugart's Minifloppy has 
been used by more small computer system 
manufacturers than any other drive. In 
fact, more than half-a-million Minifloppys 



TM— Minifloppy is a trademark of Shugarl Associates. 



have been installed. The Minifloppy looks 
small— but it stores a lot of data. 250 
kilobytes on one side, or up to 500 kilo- 
bytes in the double-sided model. That's 
about 50 pages of printed information on a 
single-sided Minidiskette, and twice that 
on the double-sided version. You'll have 
plenty of storage capacity for your pro- 
grams, letters, forms, or ledger entries. 
And you find your data fast, too, because 
the Minifloppy is a random access device 



that eliminates the need to search for your 
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which develops and markets the 
stand-alone games found in pinball 
arcades and restaurants, a 6502-based 
development system employs 
FORTH software to debug and test 
arcade circuit boards. In addition, 
Atari has developed its own custom 
version of the language, called game- 
FORTH, that is awaiting its first use 
to replace machine code as the lan- 
guage used to create arcade games. 
Someday soon, you may play a coin- 
operated game without knowing that 
you are actually running a FORTH 
program. 

In the Consumer Group of Atari, a 
version of FORTH that has been ex- 
tended to allow manipulation of the 
video screen and game peripherals 
has been developed for the Atari 800 
computer. Although no definite plans 
have been made, Atari may market it 
as an option for the Atari 800, or, like 
the Coin-Operated Division, use it in 
a "transparent" mode to implement 
games and other programs. 

• FORTH is used in a portable 
1802-based computer that aids in the 
treatment of patients with infrequent 
heart flutter. The device, small 
enough to be worn comfortably by 



the patient during his or her daily ac- 
tivities, constantly updates a "snap- 
shot" of the patient's heart activity 
every 7 seconds. In addition to re- 
cording this information in real time, 
the device analyzes the data for evi- 
dence of a heart murmur. When a 
murmur is detected, the device stores 
the data containing the evidence and 
signals the patient to return with the 
device to the doctor's office for 
analysis and diagnosis. 

• In another medical applica- 
tion, FORTH is the sole language 
used in a computer at the Cedar-Sinai 
Medical Center in Los Angeles, Cali- 
fornia. Using FORTH, a Digital 
Equipment Corporation PDP-11 /60 
simultaneously performs, among 
others, the following tasks: manages 
32 remote terminals; stores patient in- 
formation from an optical reader into 
a large data base; runs a statistical 
package that analyzes the patient 
data base in search of trends in the 
physical makeup, treatment, and 
results of similar patients; and 
analyzes blood samples and heart 
behavior in real time while a patient 
is exercising on a treadmill machine. 
Spencer SooHoo, in the pulmonary 



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medicine section, is also developing a 
portable 6800-based FORTH system 
to be used for monitoring intensive- 
care patients. 

• A stripped-down version of 
FORTH was used to create the hand- 
held Craig M100 Language Trans- 
lator under time, size, and other 
design constraints. This same lan- 
guage also runs the software inside 
the translator unit. In a related pro- 
duct, a hand-held ASCII terminal 
manufactured by MSI Data Corpora- 
tion of Costa Mesa, California, also 
uses FORTH internally. 

• In what must be the most in- 
teresting FORTH application I have 
encountered, a central California 
fruit farming cooperative uses an 
8080-based machine running FORTH 
to adaptively sort and grade peaches. 
Infrared sensors send information to 
the computer on the coloring and 
quality of pitted peach halves that 
pass the sensors on a conveyer belt. 
After analyzing this data, the FORTH 
program causes flippers to knock the 
peach halves into appropriately grad- 
ed bins — extra fancy, fancy, etc. In 
addition, the program keeps track of 
the percentage of peaches in each bin 
and changes its selection criteria to 
maintain a certain fixed ratio among 
the various grades of peaches. 

• Last but not least, FORTH is 
used in several aerospace applica- 
tions. A FORTH-like language called 
IPS (running on an 1802-based 
system) is orbiting Earth in an 
amateur radio satellite called the 
OSCAR Phase III. Avco Inc is using 
another 1802-based system (again, 
for the small size and power corn- 
sumption of the 1802 microprocessor) 
to monitor temperature and take care 
of ground-to-satellite and satellite-to- 
ground telemetry in a military 
satellite. 

Who Should Try FORTH? 

FORTH is an easy language: a high 
school student, Arnold Schaeffer, 
wrote an arcade-type game called 
BREAKFORTH. (See "Breakforth in- 
to FORTH," by A Richard Miller and 
Judy Miller, on page 150.) 

FORTH is a difficult language: it 
easily beats APL as a "write-only 
language"; you can write a program 
in the language, but you can't easily 
read what you've written. 

Given these two valid extremes, 
your initial reaction might be, "This 
doesn't make sense." True, learning 



8 AuhusI 1980 © BYTE Publications Inc 



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FORTH takes some time; it's some- 
what like learning a foreign language. 
So far, my experiences with FORTH 
remind me of my attempts at learning 
a smattering of Russian; both lan- 
guages are so different from any I've 
seen before — French or Spanish, 
BASIC or FORTRAN— that I have to 
mentally shift gears to work in the 
new language. 

You should give FORTH a try if 
you are excited by what you see here. 
Especially important in this respect 
are the articles, "What is FORTH? A 



Tutorial Introduction," by John 
James, and " A FORTH Glossary," 
pages 100 and 186, respectively. Your 
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language to demonstrate it to you. 

My first experience with FORTH 
was at the Fourth West Coast Com- 
puter Faire in May 1979. A member 
of the FORTH Interest Group was 
demonstrating the language using an 
Apple II and an Advent television 
screen. First, he defined a word called 



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COUNT, like this: 

: COUNT DO I . LOOP ; 

Then he said { 6 COUNT } (note: 
the braces are not part of the expres- 
sion; see the accompanying text box), 
the computer replied with 
{012345 OK }. I was instant- 
ly hooked on learning more about 
FORTH. What he had done closely 
paralleled the iota function in APL, 
and anything that even resembled 
APL was going to get my full atten- 
tion. 

If you are at all dissatisfied with the 
capabilities of your current com- 
puter, or if you feel that there should 
be more to computers than BASIC 
and assembly language, you should 
try FORTH. Once you get accus- 
tomed to its peculiar syntax, you can 
make it do nearly anything you want 
it to. In fact, you can even make it 
have features it did not previously 
have. Assembly language is like this 
to some extent, but FORTH is a 
higher-level language with the same 
abilities — only magnified. FORTH is 
what I call a "homebrew" language; 
its enthusiasts carry with themselves 
the same look-how-this-works en- 
thusiasm as do most hardware 
hackers who build their own hard- 
ware. If we ever have a homebrew 
software issue, FORTH will certainly 
be included. 

FORTH is the ultimate software 
hacker's language because, like a bag 
of components before a hardware 
hacker, you can do anything you 
want to with it. It can be argued that 
assembly language is the ultimate 
programming language; strictly 
speaking, this is true, but it takes so 
much more time to craft a piece of 
software in assembly language that it 
is practically ruled out in most cases. 

However, this total freedom carries 
with it complete responsibility. Since, 
for example, the FORTH program 
you write is free to use an array 
subscript that is out of bounds, you 
must be responsible enough to either 
(a) put in error-checking routines 
(you can take them out later), or (bj 
build your program up from small 
tested modules to assure that your 
program will never execute an im- 
proper subscript. If you would rather 
have the language system do this kind 
of work for you, stick to BASIC or 
whatever you're running now. 

Text continued on page 128 



10 August 1980 © BYTE Publications Inc 



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same questions about the AIO. 

We'll answer those and a few more here. 

GL Does the AIO have hardware handshaking? 
A: Yes. The serial port accommodates 3 types — RTS, 
CTS, and PCD. The parallel port handles ACK, ACK. 
BSY, STB, and STB. 

Qi What equipment can be used with the AIO? 

A: A partial list of devices that have actually been tested 

with the AIO includes: IDS 440 Paper Tiger, Centronics 

779, Qume Sprint 5, NEC Spinwriter, Comprint, Heathkit 

H 14, IDS 125, IDS 225, Hazeltine 1500, Lear Siegler 

ADM-3, DTC 300, AJ 841. 

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A: Yes. The current AIO serial firmware works great 

with Pascal. If you want to run the parallel port, or both 

the serial and parallel ports with Pascal, order our 

"Pascal Patcher Disk'.' 

Q: What kind of firmware option is available for 

the parallel interface? 

A: Two PROM's that the user installs on the AIO card 

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Variable margins, Variable page length. Variable 

indentations, and Auto-line-feed on carriage 

return. 

Qi How do I interface my new printer to my Apple 
using my AIO card? 

A: Interconnection diagrams for many popular 

printers and other devices are contained in the 

AIO Manual. If your printer is not mentioned, 

please contact SSM's Technical Support Dept. 

and they will help you with the proper 

connections. 

Q: I want to use my Apple as a dumb terminal 

with a modem on a timesharing service like 

The Source. Can I do that with the AIO? 

A: Yes. A "Dumb Terminal Routine" is listed 

in the AIO Manual. It provides for full and 

half duplex, and also checks for presence 

of a carrier. 

GU What length cables are provided? 

A: For the serial port, a 12 inch ribbon cable 

with a DB-25 socket on the user end 

is supplied. For the parallel port, a 72 inch 

ribbon cable with an unterminated user 

end is provided. Other cables are available 

on special volume orders. 

The AIO is just one of several boards 
for the Apple that SSM will be introducing 
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If you could talk to Thomas Edison, 
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Pascal, FORTRAN, PILOT and 
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Letters 



Programming Knowledge 
Is Not Enough 

Isaac Newton explained it over 300 
years ago. Introductory physics students 
learn it less than three months into their 
first course. Yet now it seems to be 
treated as an argument over words, 
rather than principles, in BYTE's Letters 
column. I speak of the description of cir- 
cular motion under the influence of 



gravity, and in particular of Delmer 
Hinrichs' recent contribution "Marsport 
Forces Resurface'' (January 1980 BYTE, 
pages 16 and 17). 

In the situation described, there is 
only one force acting: gravity, given by 
GMm/r 2 . The other relation Hinrichs 
presents does not show how to calculate 
another kind of force, but is simply a 
statement of Newton's second law of 
motion, namely, if any net force acts on 



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a body, an accelerated motion will be 
observed. For circular motion, the ac- 
celeration is equal to v 2 /r, and the force 
giving rise to such motion, from 
whatever physical source, is called a 
centripetal force; ie: a force toward the 
center of the circle, which is quite the 
opposite of Mr Hinrichs' "centrifugal" 
force (of which there is none in the 
situation under discussion). The physics 
here is thus simply to note that the 
gravitational force acts centripetally, and 
thus can be equated to m times the ac- 
celeration, or ma. 

It is unfortunate that many people 
have not yet realized that programming, 
once one is past the initial hurdles, is no 
longer a self-sufficient discipline, but 
must be viewed as a tool within the con- 
text of some other discipline in order to 
acquire real value. If the discipline is 
economics, for example, the programmer 
must be a reasonably accomplished 
economist if one is to trust his results; if 
the discipline is physics, then the physics 
must be understood thoroughly, and not 
just pulled out of some handbook; and 
so on.... 

S Leslie Blatt 
Professor of Physics 
The Ohio State University 
Van de Graaff 
Accelerator Laboratory 
1302 Kinnear Rd 
Columbus OH 43212 



More Marsport Commentary 

In Delmer Hinrichs' second letter in 
the January 1980 BYTE, he continues to 
miss the point about the nature of forces 
in circular motion. (See "Marsport, Here 
I Come," April 1979 BYTE, page 84.) As 
he points out, the National Aeronautics 
and Space Administration (NASA) ex- 
plains circular orbits in terms of cen- 
tripetal force and gravitational force, 
while Mr Hinrichs says, "The attraction 
of gravity is exactly balanced by the 
centrifugal force at all times." This is not 
just a matter of "slightly different" ter- 
minology. As can be confirmed with a 
dictionary, a centripetal force is one 
directed toward the center of motion, 
but a centrifugal force is one directed 
away from the center of motion. Thus 
the terminology of Mr Hinrichs is in fact 
opposite that of NASA. 

Perhaps the confusion results from the 
use of two names, centripetal and 
gravitational, which suggests the ex- 
istence of two forces. However, gravita- 



14 August 1980 © BYTE Publications In 



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tional forces are centripetal; ie: directed 
toward the center (of Mars in this case). 
In other words, for circular orbits the 
gravitational force and the centripetal 
force are one and the same and cannot 
balance one another. 

You might then wonder why two 
names and two formulas are used for the 
same force. The answer is that the two 
different formulas come from two 
separate types of analysis, one indepen- 
dent of motion, the other requiring mo- 
tion. The formula for gravitational 
force, F 2 = GMm/r 2 , comes from 
measurements of forces between two 
masses. The two masses might be or- 
biting each other, in contact, on a colli- 
sion course, or moving apart. The 
gravitational-force formula works the 
same in all of these cases. On the other 
hand, the formula for centripetal force, 
F, = mv It, comes from measurements 
of forces needed to keep a single mass 
moving in a circular path. These forces 
can be of any type. Examples include 
tension in a string, friction between a 
car's tires and the road surface, elec- 
tricity, magnetism, and gravity. The 
centripetal force equation works the 
same in all of these cases. Notice that 
both of these formulas apply to circular 
orbits and can be set equal because the 
centripetal force is supplied by gravity. 

As a high school physics teacher with 
a Master's degree in physics, I have 
discussed this subject with over a dozen 
physicists and hundreds of students. All 
of the physicists and most of the 
students would agree with what I have 
written here. 

Robert Reiland 

RR 1 

Portersville PA 16051 



A Message About the Reminder 

My article in the January 1980 BYTE 
"A Computer-Generated Reminder 
Message" (page 160) has prompted 
several people to contact me, raising 
various questions related to the article. 

The data conversion routines caused 
the most comment. They require a 
BASIC processor which maintains at 
least seven full decimal digits of preci- 
sion; many do not. To determine if a 
given BASIC maintains seven digits of 
precision, enter "PRINT 9999999". If 
"9999999" is printed, the BASIC main- 
tains sufficient precision. References for 
further study of data-processing 
algorithms may be found in the follow- 
ing articles: 

Fliegel and Pan Fladen, "A Machine 
Algorithm for Processing Calendar 
Dates," Communications of the 



ACM (CACM) 
October, 1968. 



volume 11, 



Robertson, "Remark on Algorithm 
398," Collected Algorithms from 
CACM. 

Stone, "Tableless Date Conversion," 
Algorithm 398, CACM, volume 13, 
October, 1970. 

Tantzen, "Conversions Between 
Calendar Date and Julian Day 
Number," Algorithm 199, CACM, 
volume 6, August, 1963. 

The only known error in the January 
article appears on page 172. The 
reference to line 9500 should be deleted, 
since the line was deleted from the pro- 
gram listing. 

Another area of questions concerned 
the conversion of the program to other 
disk BASIC s. I have been asked about 
TSC BASIC, North Star BASIC, and 
other versions. The usual two areas of 
concern are the required seven digits of 
precision and disk input/output (I/O) 
methods. Without reference to specific 
implementations, Microsoft-like BASICs 
should prove the easiest to convert. 
Other implementations which do not use 
FIELD statements are also convertible, 
though with some increase in difficulty. 

Edgar M Pass 

Computer Systems Consultants Inc 

1454 Latta Ln NW 

Conyers GA 30207 



Here's a Good Book on 
Curve Fitting 

In response to F R Ruckdeschel's 
appeal for a good, balanced reference 
book on curve fitting (Letters, March 
1980 BYTE, page 16), I heartily recom- 
mend Applied Linear Statistical Models 
by John Neter and William Wasserman 
(Richard Irwin & Sons, 1974). 

This book features a unified approach 
to both simple and multiple cases of 
linear and polynomial regression tech- 
niques, and through the use of indicator 
variables, it also offers a regression ap- 
proach to basic and multifactor analysis 
of variance. 

It is a good book for both beginners 
and statisticians alike, since it starts out 
at an introductory level, introduces 
matrix theory early, and goes on to 
show how matrix operations (o^jrations 
on two-dimensional arrays, which most 
computer languages can handle) can be 
applied to a large variety of statistical 
analyses. 

After I had struggled for years in the 
seemingly muddy area of statistics, this 
book has been instrumental for me in 



16 August 1980 © BYTE Publications Inc 



Circle 11 on inquiry card. 



Do more 

than ever before- 

spend less than 

you planned 




Heath makes the All-in-One Computer more versatile 



Many satisfied customers know 
Heath takes the risk out of buying a 
balanced computer system. With the 
Heathkit All-in -One Computer, you 
get 16K Random Access Memory 
(expandable to 48K), keyboard, video 
terminal and floppy disk system - 
together in one self-contained, com- 
pact unit - for up to hundreds of 
dollars less than comparable systems. 

Heath now makes the All -In-One 
Computer more versatile than ever! 
The new Heathkit H77 Floppy Disk 
System gives the All-in -One even 
more data storage and recall capac- 
ity. Combined, the All- In-One and 
H77 Floppy Disk give you up to 300K 



bytes of on-line data storage - 
enough to hold entire files. You can 
mount operating system and pro- 
gram disks at the same time, to make 
computing even faster. 

You can run programs written in 
MICROSOFT™ BASIC™ and As- 
sembly Languages, and all current 
software written for the popular 
Heathkit H8 Computer. 

Heath User's Group (HUG) will share 
with you a library of over 500 pro- 
grams to make your computer serve 
you in ways you never imagined. 
There's no better way to learn about 
computer systems - and save money 
- than by building one yourself. 



Heathkit 



Concise, easy-to-follow Heathkit 
assembly manuals show you the 
way, from start to finish. And a na- 
tionwide network of service centers 
protects your computer investment. 

Join the Heathkit computer family 
today - and pocket the savings! 

For complete details on Heathkit 
computer systems, as well as nearly 
400 other electronic kits for your 
home, work or pleasure, send today 
for your free, value-packed Heathkit 
catalog. Or pick up your copy at the 
nearest Heathkit Electronic Center. 



SEND FOR FREE CATALOG 



Wnte to: HEATH COMPANY, 
DEPARTMENT 334-684, 
BENTON HARBOR, MI 49022 




VISIT YOUR HEATHKIT STORE 




In the U.S. and Canada, visit your 
nearby Heathkit Electronic Center where 
Heathkit products are also displayed, 
sold and serviced. See the white pages of 
your phone book. In the U.S., Heathkit 
Electronic Centers are units of 
Veritechnology Electronics Corporation. 



CP-184 



Now for CRTs, TRS-80 Model II and Sorcerer! 

VEDIT CPM 

Visual Editor 

You Customize The Fastest Editor For 
Word Processing, C-Basic, Fortran, Assembler. 



Special Features: 

Disk buffering can automatically 
perform Read/Write for files larger 
than available main memory. 

Tabs settable to any positions. 
Tab key inserts tab character or 
spaces to next tab position. 

Display of clearly marked contin- 
uation lines for text lines longer 
than the screen. 

You Customize It: 

To Your screen size (even 40 or 
70 lines), screen address and 
keyboard layout. 

Cursor type, blinking, reverse 
video. 

Default Tab positions and various 
parameters. 

Scrolling methods. 

Its ideal for diverse hardware, 
keyboards and applications. 

For OEMs too. 

Compatible: CP/M systems with 
most memory mapped displays, 
including VDM, SSM, VIO, Matrox. 
CRT terminals, H19, VT100, 
Hazeltines, etc. Also for Sorcerer 
and TRS-80 Model II. 



Features: 

Screen oriented editor with status 
line. In visual mode the screen 
continuously displays the region of 
the file being edited and a cursor. 
Changes are made by moving the 
cursor to any place in the file and 
typing in new text or hitting a 
function key. These changes are 
immediately reflected on the screen 
and become the changes to the file. 

Full array of cursor movements 
with single key movement to begin 
and end of lines, tab positions. 

Function keys for character 
delete, line delete and allowing line 
splitting and concatenating. 

Very easy to use text move in 
visual mode with a text register. 

Flexible command mode allows 
global search and substitute, repe- 
titive editing operations, text move. 

Blocks of text are readily copied 
from one file to another. Files may 
be merged on input, split on output 
and other extensive file handling. 

Keeps up with the fastest typists! 

Extensive manual with sections 
for both the beginning and experi- 
enced user. (Our users say it is the 
clearest, best manual available). 

The Changes You Make on the Screen 
Become the Changes in the File. 

Compare with the other screen oriented editors. Some have most of VEDIT's 
features, fewer have the special features, but none are customizable like 
VEDIT. And don't be misled by our lower price! Write or call for more 
information and discover why VEDIT allows you to edit faster and easier than 
any other editor. (Even users with other screen oriented editors and word 
processors tell us they prefer VEDIT!) 

Ordering: Specify your video board, CRT terminal type or microcomputer, 
the 8080/Z80 or Z80 code version and disk format desired. 

Need a Fast and Reliable 24 X 80 Video Board 

Then you want the S-100 PIICEON V-100. Its I/O mapped, doesn't take up 
memory space, yet runs at full processor speed. Full character set with lower 
case descenders. Fully assembled and tested by PIICEON, the company 
known by OEMs for reliability. Its the ideal companion to VEDIT. 

Standard Package: For CRTs, Sorcerer, Model II, Piiceon $110 

Memory Mapped Package: For Memory mapped displays $100 

Manual: Price refunded with software purchase $ 15 

PIICEON V-100: 24 X 80 Video display board, 1 Year Warranty $445 

PICKLES & TROUT CP/M: Super CP/M 2.2 for the TRS-80 MOD II . . $185 

VISA and MASTER CHARGE Welcome. Dealer Inquires Invited. 

CompuView Products Inc. 

1531 JONES DRIVE ANN ARBOR, MICHIGAN 48105 
CALL ANYTIME: (313) 996-1299 



clearing the water. And for the ex- 
perimentally minded computerist, this 
text winds up with a comprehensive sec- 
tion on experimental design. 

Richard Shide 
918 4 Ave S 
Fargo ND 58103 



Getting Into a Metric Gear 

As an avid cyclist, I was glad to see 
the Programming Quickie in the March 
1980 BYTE ("Gear-Ratio Calculation for 
Bicycle Derailleurs," page 68), but as an 
ardent proponent of "metrication" 1 was 
sorry to see that, contrary to your stated 
policy, you did not include a metric 
equivalent. Metric countries use a more 
rational and intuitively meaningful 
measure of the gear ratio than our silly 
system does; they simply measure how 
far the bicycle will travel in one com- 
plete turn of the pedals. The following 
program (listing 1) should serve to make 
the principle clear. 

Listing 1. 

PROGRAM GEARS; 
CONST PI = 3.14159; 
VAR 
DIAMETER. 
CIRCUMFERENCE, 
DEVELOPMENT, 

CHAINWHEEL, SPROCKET: REAL; 
BEGIN WRITE ('WHEEL DIAMETER IN 
METERS; '); 
READ (DIAMETER); 

CIRCUMFERENCE : = PI * DIAMETER; 
REPEAT WRITE (TEETH ON CHAIN 
WHEEL: '); 
READLN (CHAINWHEEL); 
WRITE ('TEETH ON SPROCKET: '); 
READLN (SPROCKET); 
DEVELOPMENTS (CHAINWHEEL/ 
SPROCKET) * DIAMETER; 
WRITELN ('DEVELOPMENT: ', 
DEVELOPMENT: 4:2, ' METERS.') 
UNTIL EOF 
END. 

David A Mundie 
104 Oakhurst Cir 
Charlottesville VA 22903 



Beware of Handshakes 

If any BYTE readers are thinking 
about installing a dot-matrix printer in 
their microcomputer system, I have a 
friendly warning to pass on: pay close 
attention to your manufacturer's recom- 
mendations, or know the risk you're 
taking if you ignore them. 

For example, North Star Computers, 
Inc recommends that owners connect the 
Anadex DP-8000 to the parallel interface 
of its Horizon computer. But comparing 
printer specifications, I chose to save a 
few bucks by building a Heath H-14 line 
printer for the Horizon's serial interface. 

I saved some money: the printer kit 
cost $625 plus shipping, plus an addi- 
tional $82.98 at the Heathkit Electronic 



18 August 1980 © BYTE Publications Inc 



Circle 12 on inquiry card. 



Circle 13 on inquiry card. 



Mountain Hardware makes 

more peripherals for 

the Apple Computer 

than Anybody. 



INTROLXH 




for lights and 
chedules and 
energy conservation. Complete applications 
software package. Home security with random 
scheduler. Power usage accounting package for 
home energy cost control. No wiring required. 



ion. Interrupts 
ground operation of 
ously. Battery back-up. 
i accuracy. Onboard 
ROM for easy access from BASICS. Supports 
PASCAL. Time from one millisecond to one year. 



and . . . 

a place to put them 



Mountain Hardware 



room, or sound effect 
as well as output is un 



grams. I/O capability 
pted inputs. Use output for 
announcements in a control- 
aims. Easy to use because input 
pecial software operating system. 



•--" 



Ms. Create your own firmware. 
..PROMs. Disk software package 
provides easy EPROM programming. EPROMs are verified 
after BURN. RUN your programs from on-board socket or 
install them on ROMPLUS +. 



■'" system through firmware. Six sockets 
i or ROM equivalents. Six or any com- 
at once. Scratch-pad RAM and two TTL 
connectors. Special 2K ROMs available for powerful system 
enhancement: Keyboard Filter ROM— COPYROM— Others 
coming soon. 



vailable only on 
lainframe corn- 
eal instrumental 
music synthesizer system. 16 voices in 
stereo. Instrument definitions simulate the 
sound of real instruments — and more. Fully 
programmable waveforms. Envelope Con- 
trol. Composition system— sheet music 
input using standard music notation. 
Chords and multi-part scoring up to 16 
voices. A true instrument that anyone with 
an Apple can play. 



:o digital input. 16 
I to analog output, 
lution. Super-fast &n 
sec. conversion time. Monitor and 
output to the real world. All on one 
card. 



'XPANSION CHASSIS 



in Expansion Chassis the same way as in your 
Apple. Only one additional command to specify 
in Apple or in Expansion Chassis. Compatible with 
all Apple peripherals. 



MOUNTAIN HARDWARE has the most compre- 
hensive line of Apple peripherals available. 
Anywere. From anybody. We know the Apple 
inside and out and are committed to providing 
the most innovative and unique products to 
expand and enhance its capabilities and use. 
After all, we were the first company to make an 
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The message is simple. If you have an Apple, you 
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Available at Apple Dealers worldwide. 



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Leadership in Computer Peripherals 
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Apple is a trademark of Apple Computer Inc. 



Center in Seattle when the H-14 flunked 
its initial power-on tests. The service 
personnel replaced two defective CMOS 
(complementary metal-oxide semicon- 
ductor) integrated circuits and repaired 
three open-foil breaks in the 5 V supply 
at no charge, but they detected er- 
roneous installation of seven transistors. 
(Considering the obvious textual errors 
in the documentation, which would you 
believe — the text or the pictorials? I 
guessed wrong and followed the pic- 
torial: customer error!) 

My H-14 printer tested perfectly at 
4800 bps (bits per second) under HDOS 
in Seattle. It went ape at 4800 bps on 
the Horizon after I got it home. A quick 
phone call to my friendly Horizon dealer 
divulged the fact that North Star DOS 
does not test for handshaking signals! 
(The Heath manual advises to run no 
faster than 110 bps without hand- 
shaking.) 

So now I have a 110 bps line printer 
dawdling along, while the 4 MHz Z80A 
and 1 are twiddling our respective 
thumbs! Does anybody out there want 
to trade an in-warranty Anadex DP-8000 
printer for an in-warranty Heath H-14 
plus some extra cash? 

John R Dye 

4807 Fifteenth Ave SE 

Lacey WA 98503 



Specialized Business Program 

As a charter subscriber to BYTE, I 
quite often see references by many of 
your software reviewers and article 
writers to the lack of good software 
available for microcomputers in the 
business field. I thought, to give some 
perspective, that I would tell BYTE 
readers about the Electric Log. It is 
highly specialized and useful in no field 
other than the operation of a television 
station; therefore it is directed to a very 
small group of very small businesses 
(less than 8000 in the entire US). 

The point I would like to make is this: 
since there is an adequate supply of 
standard business packages available, the 
opportunity in business software lies in 
the specialized application field. These 
will never be marketed in magazines 
outside the trade, never by computer 
companies, and never with any great 
publicity. There is more of this done 
than you realize, and this may be the 
undercurrent that stimulates small 
business to invest in microcomputers. 

Pete Charlton 
The Management 
POB 111 

Aledo TX 76008 



Figure 1. 



16 RESISTORS 
IN SERIES 



-H- 



Pass the Pi 



Emory Sprenkle remarked in his letter 
(February 1980 BYTE, page 16) that 
1/(113/355) is a good rational approx- 
imation of ir, and is easily remembered. 
In fact, 355/113 is the best rational frac- 
tion approximation to 7r having no more 
than three digits in the numerator. 

I was reminded of the following prob- 
lem which appeared a few years ago in 
American Mathematical Monthly: 

What is the smallest number of 
perfect 1-ohm resistors needed to 



create a network with an equivalent 
resistance of t ohms, ± 10 " 6 ohms? 

This problem leads one to discover how 
positive rational fractions may be 
presented as continued fractions .The 
solution shown in figure 1 includes three 
resistors in series with a network con- 
sisting of sixteen series-connected 
resistors in parallel with seven parallel- 
connected resistors, making twenty-six 
in all. 

W Lloyd Milligan 
8604 Maywood Dr 
Columbia SC 29209 ■ 



Industrial quality components 
for S-100 system builders, from 
California Computer Systems. 



Distt Cuntrottei '■ 
density controller for up to four Sy" or 8" 
single-sided drives, or two double-sided drives. 
Shipped with CP/M 2.0, the controller reads 
and writes IBM-standard single density. 
Automatically determines disk density— 
single or double. Supports PerSci auto eject, 
plus fast-seek for voice coil systems. 

2810 Z80 CPU Board. Capable CPU for S-100 
Systems operates at 2 or 4MHz, is fully Altair/ 
Imsai compatible, Z-80 monitor is available 
separately. Includes auto addressing to 
4K boundaries, plus a serial port for serial 
devices, including terminals and printers. 
Supports both front-panel operation and 
power-on memory jump, plus wait-state gen- 
eration for slower memories. Compatible with 
proposed IEEE S-100 standards. 

2032A 32K Static RAM. Fast static memory 
operates without wait states at a full 4MHz. 
Supports full and partial bank select, for 
expansion beyond 64K. Addressable in 8K 
blocks at 8K boundaries. Address and data 
lines are fully buffered, and there are no 
DMA restrictions. 

201 6 16K Static RAM. Fully buffered board 
features 2114 static RAMs for +5v operation. 
Bank select available by bank port or bank 
byte, for system expansion beyond 64K. 
Addressable in 4K blocks at 4K boundaries. 
LED indicators for board selection and 
bank selection. Available in 200, 300, or 450 
nsec versions. All versions support 4MHz 
operation with no wait states. 

2200A Mainframe. Rock solid, heavy gauge 
cabinet includes 12-slot, actively terminated 
S-100 motherboard, fan, and power supply. 
Fbwer supply features 105, 115, or 125 volt 
AC input power; provides +8vDC at 20 amps, 
± 16v DC at 4 amps. Available in five colors. 
Includes convenient, front mounted, lighted 
reset switch. 

2501A Mother Board. 12 slots, actively 
terminated, with all S-100 connectors included. 
Distributed power line bypass, low induc- 
tance interconnect— extremely low bus noise. 

Prototype Boards. Four high quality prototype 
boards: Solder Tail, Extender/Terminator, 
Wire Wrap, and Etch. 

P2802AA6502 CPU. Stand-alone CPU 
generates fully S-100 compatible I/O signals; 
executes 6502 machine language. Operates at 
2MHz; capable of DMA operation. 



Available nationally. 

California Computer Systems industrial 
quality S-100 products are available at over 
250 computer retailers. Volume customers 
should contact the marketing department at 
CCS. 



CCS. Industrial standards. 



20 August 1980 © BYTE Publications Inc 



Circle 14 on inquiry card. 



the S-]fifi 





9 



We mass-produce S-100 

products to deliver industrial 

quality, at industrial prices. 

You systems builders who need top quality, full 
featured, workhorse S-100 building blocks at the most 
competitive prices now have a source. California 
Computer Systems. 



Industrial quality means top grade materials, com- 
ponents, and assembly, plus complete testing for absolute 
reliability. 

Industrial quality means solid designs, a full 
complement of the important features you require, and 
a product line that delivers performance. 

Industrial pricing comes from mass production. We 
buy at the right prices, and build in quantity, using 
state-of-the-art facilities and techniques. Including 
complete burn-in, for full performance right off the shelf. 

Our industrial point of view means you get higher 
performance, greater reliability, and lower prices. If these 
are features you would like to see in your S-100 system, 
see things our way. 

Because for serious users with serious uses for 
the S-100, these are the industrial standards. 



5 



California Computer Systems 

250 Caribbean Sunnyvale, CA 94086 (408)734-5811 



Gispcis's Circuit Cellar 

Copyright © 1980 by Steven A Ciarcia. All rights reserved. 



A Build-It-Yourself Modem 
for Under $50 



Steve Ciarcia 

POB 582 

Glastonbury CT 06033 



I receive many personal-computer 
club newsletters. Some of the larger 
clubs around the country have put me 
on their mailing lists to keep me 
informed of what's going on in their 
area. One I recently received was 
significant because it demonstrated 
the tremendous advancements in per- 
sonal computing in a very subtle 
way. 

It was not the content of this 
newsletter that was important. It con- 
tained the usual new business, old 



business, and other information. The 
significant point was the preparation 
of the document itself. 

According to an editorial, this 
publication has an editor/publisher 
and four columnists spread across the 
state. Each columnist prepares his 
textual material on his own personal 
computer, using a word-processing 
program. He then telephones the 
editor's computer and down-loads the 
text to it. The editor, using his com- 
puter, combines the four individual 




Photo 1: The prototype modem circuit of figure 1 was assembled on the blue perforated 
circuit board as shown. It was then installed under the top cover of a COMM-80 I/O- 
e.xpansion unit, shown at left. The COMM-80 was described in the June Circuit Cellar. 
(See "I/O Expansion for the TRS-80, Part 2: Serial Ports," June 1980 BYTE, page 42.) 
The COMM-80 and this modem are sufficient to turn a Radio Shack TRS-80, or a com- 
puter that uses a similar bidirectional bus, into a timesharing terminal. The modem can 
be used on any computer. 



columns, along with his work, and 
lays out the complete newsletter. 
Finally, the editor telephones the 
print shop and transmits the entire 
newsletter for typesetting and print- 
ing. 

The significant point is that all the 
communication is between computers 
and is conducted over the telephone 
lines. 

Transmitting and receiving data 
using the telphone is not a difficult 
task if you have the correct equip- 
ment. Virtually any microcomputer 
can be configured for this activity. To 
communicate properly, the system 
must be a serial terminal or emulate 
one and be attached to the phone 
lines through a modem. 

A "terminal" describes any equip- 
ment with hardware and software 
designed to facilitate serial data com- 
munication with prescribed data rates 
and protocol. My June 1980 article on 
the COMM-80 was such a hardware 
package. (See "I/O Expansion for the 
TRS-80" June 1980 BYTE, pages 42 
thru 62.) With the COMM-80 attach- 
ed and using the communication soft- 
ware provided, the TRS-80 computer 
emulates a terminal. Any other com- 
puter system calling itself a 
"terminal" and using the same data 
rates and protocol would be able to 
communicate with it. This includes 
all users of The Source and MicroNet 
timesharing services. 

A modem is the device that allows 
the computer to be connected to a 
telephone. 

The problems associated with con- 
necting your computer to a telephone 



22 August 1980 ; BYTE Publications lnc 



There are two 
sides to our story. 



Side One 

The DISCUS 2+2 Quad-Density Hardware 



Now you can use your 
S-100 system to tackle big 
jobs. Because the DISCUS™ 
2+2 Quad-Density Disk 
System puts 1.2 megabytes of 
fast-access memory on your 
side for just $1545.00 complete. 

With the DISCUS™ 2+2 System, 
complete means complete. 

You get a full-size (IBM- 
compatible 8") double-sided/ 
double-density disk drive, 




factory mounted in a cabinet with 
power supply, fully-buffered S-100 
single-board controller, and inter- 
connecting cables. All fully 
assembled, system-tested and 
fully warranteed. 
You get the speed and 
efficiency of 1.2 megabyte- 
per-diskette memory. . . 
and you get it for 0.13$ 
per byte. 



Side Two 

The DISCUS 2+2 Quad -Density Software 



1.2 megabyte quad-density hard- 
ware is only one side of the story. 
The DISCUS™ 2+2 System price 
includes all the fully-interfaced, 
high-performance software you 
need to take full advantage of your 
quad capacity. 

The system includes our exclusive 
BASIC-V™ virtual disk BASIC, which 
allows you to address your quad- 
density diskettes as easily as main memory. The 
operating system you get is the widely accepted 
CP/M* 2.1 . And you get our powerful DISK-ATE 
text editor/assembler; The most advanced software 




development tool available. 

Micro-Soft BASIC 5.1 and Micro- 
Soft FORTRAN are available as 
options. Both run under CP/M* 2.1. 
Check out the full system price of 
DISCUS™ 2+2 Quad against any 
other floppy disk system at your 
local computer store. At $1545.00, 
we think you'll take sides with 
DISCUS™ 2+2. 
If your dealer doesn't carry THINKER TOYS 
products, write MORROW DESIGNS Inc., 5221 
Central, Richmond, CA 94804. Or call (415)524-2101 
9 - 5 weekdays ( Pacific Time). 



9 



MORROW DESIGNS 7 Thinker Toys 



*CP/M is a trademark of Digital Research. 



Circle 15 on inquiry card. 




Photo 2: Comparison of two generations of modems. At right is an early model made 
by Anderson-] acobson, shown with the covers open. The old modem uses discrete 
semiconductor components and toroidal inductors. On the left is an example of a cur- 
rent model of modem: a Novation Cat acoustic-coupled modem, which is popular with 
home-computer hobbyists. 




Photo 3: First of a series of photos (3 thru 9) showing how you can easily contruct an 
acoustic-coupler pickup. My design for the pickup uses such "exotic" materials as a hot- 
water pipe foam insulation, a pair of 2-inch, 8-ohm dynamic speakers, a foam-backed 
dinner placemat, rubber cement, and adhesive tape. 

Step 1 of the process (shown here) is to cut a wedge-shaped piece from the insulating 
foam. The foam I used had an inside diameter of 1% inches with a Yz-inch wall, giving an 
outside diameter of about 2% inches. The high side of the wedge should have a height of 
about 1 inch, the low side about % inch. 

Next, cut and trim a rectangular piece of foam measuring V 2 by % by 3V 2 inches. This is 
used to help fit the speaker snugly into the hole in the wedge-shaped piece previously 
cut. 

Solder the electrical connections to the speaker before proceeding to apply rubber- 
cement to the rectangular foam piece and wrap it around the voice coil of the speaker. 
Hold it in place until the cement sets. 



are not unlike those associated with 
the cassette data-storage system on a 
personal computer. Like the 
telephone, the cassette recorder is 
incompatible with digital data and 
has a very narrow bandwidth (a few 
thousand hertz). Since all personal 
computers accommodate cassette 
data storage, there is obviously a 
reasonable solution. 

Rather than using digital voltage 
levels, as in a direct-wired com- 
munication link, audio-frequency 
tones are recorded instead. In most 
systems, one tone of a given fre- 
quency signifies a logic and a tone 
of a different frequency signifies a 
logic 1. When we change or shift the 
tones to correspond with the logic 
input, we are performing frequency- 
shift-keyed (FSK) modulation. When 
we play back the tape into the com- 
puter, a demodulator distinguishes 
the tones and separates them back 
into Is and Os. 

How Does a Modem Work? 

Terminal-to-terminal communica- 
tion is more complex than a simple 
cassette system even though it 
employs similar techniques. Trans- 
mission over the two-wire phone 
system from one terminal, called the 
originating terminal, to another, 
called the answering terminal, uses 
FSK tones. The major distinction is 
that terminals, unlike cassette 
recorders, can operate in full-duplex 
mode and communicate in both direc- 
tions over the same pair of wires. 
Rather than using a single pair of 
tones, which would be confusing if 
both terminals tried to transmit at the 
same time, a modem uses two sets of 
tones. 

One set of tones (1070 Hz and 1270 
Hz) is used by the originating ter- 
minal and another (2025 Hz and 2225 
Hz) is used by the answering ter- 
minal. If your computer were con- 
nected to a timesharing computer, 
your computer would be the 
originating system and all your data 
would be sent with FSK tones of 1070 
Hz and 1270 Hz for logic and 1, 
respectively. The timesharing com- 
puter would answer you with 2025 
Hz (logic 0) and 2225 Hz (logic 1) FSK 
data. 

Almost universally, if you are dial- 
ing up a large computer network, you 
are the originating terminal. An 
originate-only modem, which is all 

Text continued on page 28 



24 August 1980 © BYTE Publications Inc 



Circle 16 on inquiry card. 



The trouble with video terminals today 
is that most of the low-cost models just don't 
have the performance to handle your tough 
applications. And the few that do are usually 
not compatible with your existing system. But 
now, Intertec has resolved this age old 
dilemma with the introduction of its new 
Emulator™ Video Terminal. 

The $895* Emulator™ performs exactly 
as you command. With the depression of just 
a few keys, Emulator users can select 
terminal control codes of any one of four 
popular video terminals. The Lear-Siegler 
ADM-3A. The Soroc 1Q-120. The DEC VT- 
52. Or the Hazeltine 1500. Incredible! It's like 
having four terminals for the price of one. 



But, best of all, not only does the 
Emulator replace these terminals, it outper- 
forms them by offering enhanced user- 
oriented features. Features that those other 
terminals just don't have - at any price. 

Standard Emulator™ features include: a 
sharp, crisp 12" non-glare screen with a full 
24 line by 80 column display. Twin RS232C 
serial ports - one for the host computer and 
one for your printer. Four separate cursor 
control keys. A separate 18 key numeric pad. 
Keyboard selectable baud rates and operating 
modes. And, a host of visual attributes. 

No matter which dumb or smart terminal 
you're using today, don't buy another until you 
check out our new Emulator™. You'll get the 



performance of four terminals for the price of 
one. And you'll probably save hundreds of 
dollars over the price you paid for your last 
terminal. Plus, you'll get unparalleled relia- 
bility, nationwide service and quick delivery. 
Call or write us today for all the details. 
Intertec terminals are distributed worldwide 
and may be available in your area now. 



iE INTERTEC 



Warn 



< SYSTEMS. 

2300 Broad River Rd, Columbia, SC 29210 
(803) 798-9100 TWX: 810-666-2115 




^Quantity one - Dealer inquiries invited. 



S3 

§ 



s< 




CU "B 


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26 AugusI 1980 ® BYTE Publications Inc 



Circle 17 on inquiry card. 



Now! North Star 
Application Software! 



North Star now offers application 
software for use on the HORIZON! 
Now you have one reliable source 
for both hardware and software 
needs! The first packages avail- 
able are: 

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NorthWord is a simple-to-operate 
word processing system designed 
for use with the popular North Star 
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document typing time and cost. 
NorthWord incorporates the most 
sought-after word processing fea- 
tures: easy editing, on-screen text 
formatting, simultaneous document 
printing, and much more. NorthWord 
can be integrated with other North 
Star software packages to produce 
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reports quickly and efficiently. 




MailManager — 

MailManager enables you to com- 
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corrections and deletions are easily 
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InfoManager — 

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oriented, data management system. 
It will accept up to 50 categories of 
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maintains general ledger accounts 
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NorthWord is the central building 
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Berkeley, CA 94710 
(415) 527-6950 
TWX/Telex 910-366-7001 




MODULATOR SECTION 



Number 


Type 


+ 5 V 


GND 


-12 V 


+ 12 V 


IC1 


LM741 






4 


7 


IC2 


MC1458 






4 


8 


IC3 


XR2211 




4 




1 


IC4 


CD4011 


14 


7 






IC5 


NE567 


4 


7 






IC6 


LM386 


6 


4 






IC7 


LM741 






4 


7 



RS-232C f- ,,, 



1N914 




SPEAKER 



1 ^ i ^ 



CARRIER DETECT 
FROM FIGURE 1A 



Figure lb: Modulator section of the modern circuit in schematic form. The tone frequency for a mark (1270 Hz) is set up by choosing 
the proper values for capacitor C2 and adjusting the 20 k-ohm potentiometer. When transistor Q2 gates capacitor Cl in parallel with 
C2, the oscillator frequency changes to 1070 Hz. 

Capacitor Cl (0.0037 jiF) may be formed from a parallel combination of two components, a 0.0015 /if and a 0.0022 [iF part. For use 
in the answer mode, the proper value for capacitor Cl is 0.001 fiF, and the value for C2 is 0.01 fiF. 

If RS-232C communication is not a necessity, transistor Q3 may be omitted from the circuit. 



Text continued from page 24: 

you need in this instance, has a 
1070/1270 Hz modulator and a 
2025/2225 Hz demodulator. On stan- 
dard dial-up telephone lines the 



acceptable speed limit is 300 bits per 
second (bps). 

An answer modem is necessary 
when someone else calls you and 
chooses the originate frequencies for 





gUBBE 
CEME- 

~' r ARTISTS "i 
DESIGNERS 




Photo 4: Apply rubber cement to the outside of the wedge-shaped piece of pipe 
insulation. 



himself. In the answer mode, the 
modulator uses 2025/2225 Hz and the 
demodulator uses 1070/1270 Hz. 

The choice is arbitrary: either 
modem can use originate mode or 
answer mode so long as they don't 
both use the same mode. Owning an 
originate-only modem is not a handi- 
cap as long as someone trying to com- 
municate with you can set his modem 
to the answer mode to accommodate 
you. 

The modem attaches to the serial 
input/output (I/O) port on the com- 
puter. Most serial ports use the RS- 
232C protocol, and most commercial 
modems also use RS-232C. While 
there are various handshaking 
requirements listed in the complete 
RS-232 specification, for the most 
part handshaking is ignored in simple 
full-duplex modem applications. 
Usually the only signals required for 
operation, beyond the data itself, are 
Carrier Detect and Data Set Ready. 



Build Your Own Originate 
Modem 

Gaining the capability to dial up a 



28 August 1980 © BYTE Publications lnc 




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BYTE August 1980 29 



IC1 



IC2 



IC3 



IC7 



/A 


MICROPHONE 










BANDPASS 
FILTER 




DEMODULATOR 




* 

RS-232C 
CONVERTER 


SERIAL 


/ ; \U 










(2025/2225 Hz) 




OUT 














IC4 














TELEPHONE 
HANDSET 




CARRIER 
DETECT 
















U 








MUTING 
IC6 ,, 






IC5 




Q3 




\VT\ 


SPEAKER 










MODULATOR 




* 
RS-232C 
CONVERTER 


SERIAL 


V 














(1070/1270 Hz) 




IN 



Figure 2: Block diagram of the originate-only modem presented in this article. The blocks marked with asterisks (*) indicate the com- 
ponents that provide RS-232C compatibility; these may be left out of the circuit if RS-232 communication is not needed. 



national timesharing network or 
phone any of a hundred computer- 
information services on your per- 
sonal computer is a significant 
milestone. When connected to these 
systems, _you go beyond the hardware 
limits of the personal computer and 
instantly add large-computer 
capabilities. Figure 1 is the schematic 
diagram of a 0-to-300 bps originate 
modem which meets all the 
requirements for communicating with 
these systems. The prototype is 
shown in photo 1, mounted under the 



top cover of the COMM-80 
serial /parallel interface. 

There are two kinds of modems: 
direct-connect and acoustic-coupled. 
The former type requires attachment 
to the telephone wires through a data- 
coupler transformer. The latter type, 
the use of which has fewer legal 
strings attached, employs an acoustic 
coupler. This is nothing more than a 
speaker and microphone that sit 
under the mouthpiece and earpiece of 
the telephone handset. The speaker 
transmits the modem's output tones 





ffef 




Photo 5: Adding pliable material to produce a tight fit around the phone handset. I 
found a plastic placemat at a discount store with a V s -inch foam backing that was 
perfect. Cut a strip 1Y 2 by 8 inches and glue this around the outside of the wedge as 
shown. Trim to the exact circumference and cover with a strip of fabric adhesive tape. 
The latter helps hold everything together. 



into the telephone, and the 
microphone listens for the other ter- 
minal's response. 

Modems vary in complexity. Fif- 
teen years ago they were very expen- 
sive and contained many discrete, 
precision components, including 
many toroidal inductors for the filter 
circuits. Photo 2 shows, on the right, 
an old Anderson-Jacobson modem. 
Newer technology is shown on the 
left: the Novation Cat, which is prob- 
ably the most popular acoustic 
modem around. The reduction in size 
is accomplished through integrated- 
circuit technology. 

Figure 2 is a block diagram of the 
modem circuit in figure 1. The design 
I am presenting takes advantage of 
advanced technology and uses only 
six integrated circuits for the com- 
plete modem. Two additional RS- 
232-converter devices can be added if 
RS-232C interfacing is required. 

The modem is divided into two sec- 
tions: modulator and demodulator. It 
also features carrier detection and 
automatic muting. A light emitting 
diode (LED) lights to signify that the 
answering modem is on the line and 
connected when the 2025 Hz tone (the 
"carrier") is detected on the line. A 
signal generated upon detection of the 
carrier automatically enables the 
modulator output (of the 1070 Hz 
tone) in response. Without this fea- 
ture, the 1070 Hz tone would be blar- 
ing out of the speaker continuously. 

The modulator section of figure lb 
is not very difficult to understand. 
Tone decoder IC5 (an NE567 device) 



30 August 1980 © BYTE Publications lnc 




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Your computer, a color tv set and the Percom Electric Crayon 1 



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As shipped, the Electric Crayon™ 
interfaces a TRS-80* computer via 
your Expansion Interface or Printer 



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for interfacing to any computer or to 
an ordinary parallel ASCII keyboard. 

But that's not all 

The Electric Crayon is not just a 
color graphics generator/control- 
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• A 34-conductor ribbon 
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• RAM chips for adding re- 
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• Electric Crayon™ 
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of proportioned picture ele- 
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SYSTEM REQUIREMENTS: the video cir- 
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antenna input may be constructed by add- 
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Prices and specifications subjec! to cnange without notice. 




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211 N KIRBY GARLAND. TEXAS 75042 
(2141272-3421 



,M = trademark of Percom Data Company, Inc. 

• = trademark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company. 

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or to order direct if there is no Percom dealer in your area. 



Circle 18 on inquiry card. 



BYTE August 1980 31 



e inO 




• C> E OUT 



w = 2w f 



BANDWIDTH B=2/R 3 C 



GAIN 


G=-R 3 /2R! 


FACTOR 


Q=f /B 


CENTER FREQ. 


w* = 1/R 3 C 2 (1/R 1 +1/R 2 ) 




FOR: Ri = 6.2k R 2 = 510J1 R3=120k C=0.01/iF 




CALCULATED PARAMETERS: 




B=265 Hz 




G = -9.7 




Q = 8 




f = 2117Hz 



CL 

< 



A/72" 



TYPICAL BANDPASS FILTER 
RESPONSE CURVE 



B 



FREQUENCY 



FOR AN ANSWER MODEM WITH 
f = 1170Hz USE: 

R 2 = 9ion 

R 3 =220k 
C = 0.01^F 



Figure 3: The multiple-feedback, second-order bandpass filter: schematic diagram, response curve, and parameter-value calculation 
for given center-of-passband frequency. 



is configured as a very stable current- 
controlled triangular-wave oscillator. 
The space frequency (1270 Hz) is 
determined by the setting of the 20 
k-ohm 10-turn potentiometer and 
capacitor C2. In response to a logic 1 
input (inverted from logic by IC4c) 
transistor Q2 gates capacitor Cl in 
parallel with C2. The oscillator fre- 
quency will now be 1070 Hz. This 567 



oscillator, while very stable, has a 
high-impedance output. One section 
of the CD4011 NAND gate (IC4d) is 
used as a high-impedance linear 
amplifier to match the output of 
IC5 to the 50 k-ohm impedance in- 
put of IC6, the LM386 amplifier. 
Also connected to pin 13 of 
the CD4011 is the carrier-detect 
signal, which mutes the tone output 




Photo 6: Insert the speaker into the hole and align it with the angle of the foam wedge. 
In the unit shown, I used a black broad-tip marker to darken the white surfaces on the 
inside. 



when no 2025 Hz carrier is being 
received. 

The demodulator section of figure 
la is more complicated and accounts 
for the major expense in a modem. In 
an acoustic demodulator there are 
three basic sections: preamplifier, 
bandpass filter, and demodulator. 
Either a crystal microphone or a stan- 
dard 8-ohm speaker (the latter of 
which is really about the same thing 
as a dynamic microphone) can be 
used with this circuit. 

The output of the speaker/mike is 
amplified by ICl, an LM741. You 
may not need the gain provided by 
this circuit (22 X) if you're using a 
crystal mike. In that case you should 
eliminate ICl and the 10 k-ohm and 
220 k-ohm resistors, and feed the 
microphone output directly to the 
6.2 k-ohm resistor leading to IC2. In 
either case, the signals acquired by 
the mike are sent through a sharp 
bandpass filter which passes only 
signals between 2000 Hz and 2250 Hz. 

We use an MC1458 operational 
amplifier (IC2) to construct a 
multiple-feedback, second-order 
bandpass filter. IC2 is configured as 
two such elements, cascaded to 
improve response. The mathematical 
calculations behind component selec- 
tion in this type of filter are outlined 
in figure 3. The objective is to pro- 



32 August 1980 © BYTE Publications lnc 



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function. First, the tool wraps 30 AWG( 0,26mm) wire onto standard .026 inch 
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finally, it strips 30 AWG wire nick-free. 
WSU-30M makes a "modified" style of wrap, in which approximately 1 J turns 
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This unique tool is remarkable value performing the work of three separate 

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Tel. (212) 994-6600 Telex 125091 

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New York State residents add applicable tax 



Circle 19 on inquiry card. 



BYTE August 1980 33 




SIGNAL INPUT 
?4 



LOCK-DETECT 
OUTPUTS 

5 

-OQ 



ORIGINATE MODEM 
fj =2025 Hz 
f 2 =2225 Hz 

Rl=200k 

R0=18k 

Cl = 0.0047n.F 

CF=0.005^.F 

C0=0.022/iF 



ANSWER MODEM 
^ = 1070 Hz 
f 2 =1270Hz 

Rl = 100k 

R0 = 18k 

C1 = 0.01^F 

CF = 0.005/iF 

CO = 0.039/j.F 



Figure 4: Block diagram of the XR2211 phase-locked loop component, which is IC3 in figure la. Appropriate component values for 
the two modem modes are shown. 



duce a filter with a center-of- 
passband frequency midway between 
2025 Hz and 2225 Hz, with a band- 
width wide enough to allow these two 
frequencies to pass easily but reject 
everything else. The computed filter 
has a center frequency of 2117 Hz, a 
total gain factor of about 95, and a 



bandwidth of 300 Hz. When the 
telephone handset is inserted in the 
coupler, nothing is passed except the 
tones we want. 

The output of the filter is sent to 
IC3, which is an XR2211 monolithic 
phase-locked loop (PLL) especially 
designed for FSK data communica- 




Photo 7: Cutting the grill cloth. The stiff canvas used for needlepointing is ideal. Cut a 
circular piece and fit it to cover the speaker. 



tion by Exar Integrated Systems. 
Figure 4 presents a block diagram of 
this device with pertinent external 
component selection. 

A phase-locked loop is basically an 
electronic servo loop consisting of a 
phase detector, a low-pass filter, and 
a voltage-controlled oscillator 
(VCO). Its function is to synchronize 
its own oscillator to the incoming 
signal. If the incoming signal changes, 
the phase-detector output changes 
correspondingly to adjust the VCO to 
track the signal. In the XR2211, if the 
signal amplitude at the locked fre- 
quency is above a minimal value, the 
FSK comparator signifies this condi- 
tion with a binary 1 output. The 
XR2211 can accommodate analog 
input signals between 2 mV and 3 V. 

As shown in figure 1, the com- 
ponents are chosen for originate fre- 
quencies, and the XR2211 is powered 
by +12 V. (The specification says 
anything between +4.5 V and 
+ 20 V is acceptable, but +5 V is 
marginal in my experience.) 

Alignment is simply a case of 
adjusting the 5 k-ohm potentiometer 
(R4). With a 2225 Hz signal applied 
to the microphone input, adjust R4 
until pin 7 of IC3 goes low. Changing 
the input frequency to 2025 Hz 



34 August 1980 © BYTE Publications Inc 



Circle 20 on inquiry card. 



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should make this pin go high. 

In addition to the FSK output on 
pin 7, there is a lock-detect output on 
pin 5, used to denote carrier detec- 



tion. It is connected to one section of 
the CD4011. This circuit is a 
l-second-on/2-second-off delayed- 
trigger monostable multivibrator 




Photo 8: The final assembly can be spray-painted black as I have done, but this is not 
necessary. Caution: some paints act as solvents on foam and will produce a sticky mess. 
Test a small sample before spraying the whole unit, and don't spray the speaker cone. 



(one-shot). Either tone (considered 
the carrier in this case) has to be pre- 
sent for at least 1 second to trigger the 
circuit into operation, allow data to 
flow from the modem to the terminal, 
and turn on the modulator amplifier. 
IC7 and Q3 are added for RS-232C 
interfacing. If RS-232C communica- 
tion is not a requirement, then these 
parts can be eliminated. Using the 
CD4011 (IC4b), the circuit can direct- 
ly drive one low-power Schottky (LS) 
transistor-transistor logic (TTL) input 
load. A CD4049 inverting buffer or 
CD4050 buffer can be added to drive 
more input loads if necessary. 

Construction Hints 

We are dealing with high 
impedances and critical capacitances 
in this modem circuit. Layout should 
be compact, and Mylar or 
polystyrene capacitors should be used 
where indicated. Shielded cable 
should be used between the 
microphone and the modem board to 
reduce electrical-noise interference. 

The acoustic coupler can be sal- 
vaged from an old modem, such as 
the Anderson-Jacobson unit 




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* 200NSEC4116RAMS. 

* FULL DOCUMENTATION. 

. ASSEMBLED AND TESTED BOARDS ARE 
GUARANTEED FOR ONE YEAR AND 
PURCHASE PRICE IS FULLY REFUNDABLE IF 
BOARD IS RETURNED UNDAMAGED WITHIN 
14 DAYS. 

ASSEMBLE!)/ 
TESTED 

64KRAM S595.00 

4BK RAM S529.00 

32KRAM S459.00 

16KRAM S389.00 





S100 MAINFRAME 
AND CARD CAGE 



* W/ SOLID FRONT PANEL $239.00 

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. 30 AMP POWER SUPPLY $119.00 

•8 SLOT MOTHERBOARD S149.00 

•19 SLOT MOTHERBOARD S199.M) 



16K MEMORY EXPANSION KIT 
ONLY $59 
FOR APPLE, TRS-80 KEYBOARD, EXIDY, 
AND ALL OTHER 16K DYNAMIC SYS- 
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DEVICES. 

• 200 NSEC ACCESS, 375 NSEC CYCLE 

• BURNED-IN AND FULLY TESTED 

* 1 YR. PARTS REPLACEMENT 
GUARANTEE 

* QTY. DISCOUNTS AVAILABLE 



VISTA V-Z00 MINI-FLOPPY SYSTEM 
S100 DOUBLE DENSITY CONTROLLER 
204 KBYTE CAPACITY FLOPPY DISK 
DRIVE WITH CASE & POWER SUPPLY 
MODIFIED CPM OPERATING SYSTEM 
WITH EXTENDED BASIC 

SB95.00 
EXTRA DRIVE, CASE & POWER SUPPLY 

$395.00 



COmPUTER DEVICES 

1230 W.COllinS AVE. 

ORAflGE, Cfl 92668 

(714)633-7280 



xepted. Pie 

k. Phone or 

>lll be added to all at 



days (or checks i< 
. Shipping charge 



32K BYTE MEMORY 
RELIABLE/COST EFFECTIVE EXPANBABLE RAM FOR 
6502 AN0 6BO0 SYSTEM-AIM 65-'KIM*SYWPET-S44-BUS 
. PLUG COMPATIBLE WITH THE AIM-65/SYM EXPANSION 
CONNECTOR BY USING A RIGHT ANGLE CONNECTOR 
(SUPPLIED) MOUNTED ON THE BACK OF THE MEMORY 
B0AR0. 

* MEMORY BOARD EDGE CONNECTOR PLUGS INTO THE 
6800 S 44 BUS. 

* CONNECTS TO PET OR KIM USING AN ADAPTOR CABLE. 

* RELIABLE-DYNAMIC RAM WITH ON BOARD INVISIBLE 
REFRESH-LOOKS LIKE STATIC MEMORY BUT AT 
LOWER COST AND A FRACTION OF THE POWER 
REQUIRED FOR STATIC BOARDS. 

* USES *5V ONLY. SUPPLIED FROM HOST COMPUTER 

« FULL DOCUMENTATION ASSEMBLED AND TESTED 
BOARDS ARE GUARANTEED FOR ONE YEAR AND 
PURCHASE PRICE IS FULLY REFUNDABLE IF BOARD IS 
RETURNED UNDAMAGED WITHIN 14 DAYS. 

ASSEMBLED WITH 32K RAM J4I9.00 

S WITH 16K RAM J349.D0 

TESTED WITHOUT RAM CHIPS $279.00 

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BARE BOARD 8, MANUAL $49.00 




PET INTERFACE KIT-CONNECTS THE 32K RAM BOARD TO 
A 4K OR 8K PET. CONTAINS: INTERFACE CABLE, BOARD 
STANDOFFS, POWER SUPPLY MODIFICATION KIT AND 
COMPLETE INSTRUCTIONS $49.00 



U.S. PRICES ONLY 



36 August 1980 © BYTE Publications Inc 



For years many small business system buyers 
thought that in order to get "real" performance 
and enough storage to be a "real" business system 
they would have to sacrifice the family jewels. 

But with the introduction of the Smoke Signal 
Chieftain series office computers a lot of people's 
minds have been changed. 

Because we designed the highly reliable 
Chieftain small business system with the most 
innovative combination of performance and effi- 
ciency around. 

At your fingertips there are 64,000 characters 
of random access memory and you can address 
anywhere from 740,000 characters to 2 million 
characters with Smoke Signals's new double den- 
sity controller. For larger concerns, there's a 20M 
byte hard disk available. 

At a time when other small computer manu- 
facturers tell you "you're on your own", Smoke 
Signal offers an abundance of easy-to-use software 
programs such as order entry, inventory control, 



accounts receivable, invoice entry, payroll, word 
processing and much, much more. There's BASIC, 
COBOL and FORTRAN - even a multi-user BOS 
(Business Operating System) that allows for 
numerous users simultaneously. 

Chieftain systems 
starting at under $200.00 
per month display per- 
formance on par with sys- 
tems costing twice to 
three times as much. 

So call (213) 889-9340 
for your nearest autho- 
rized Smoke Signal dealer — he'll be glad to 
demonstrate the Chieftain's high reliability and 
ease of operation. For dealers only, circle 22 

All other inquiries, circle 21 






SMOKE SIGNAL m, BROADCASTING 

31336 Via Colinas, Westlake Village. California 91361. (213) 889-9340 



y_ 




4r 



I 



Circle 23 on inquiry card. 



^T 



CP/A 



OPTIMIZED SYSTEMS 
SOFTWARE 

PRESENTS 

CONTROL PROGRAM/APPLE 
the DOS you have been waiting for 

OSS CP/A is an all new, disk-based 
operating system which provides 
commands and utilities similar to 
CP/M*. CP/A has byte and block I/O, a 
simple assembly language interface, 
and direct access via Note and Point. 
And it's easy to add your own com- 
mands or device handlers. CP/A is 
expandable, flexible, consistent, 
easy-to-use and available now with 
compatible program products: 

BASIC — Some of the features of OSS 
BASIC are syntax checking on program 
entry, true decimal arithmetic (great for 
money applications), 32K byte string sizes, 
flexible I/O, long variable names (up to 255 
significant characters), and the ability to get 
and put single bytes. 

BUSINESS BASIC WITH PRINT USING — 

This is virtually the only basic available on 
the Apple that has PRINT USING. It also 
has record I/O statements and all the 
features of our standard BASIC. 

EDITOR/ASSEMBLER/DEBUG — OSS 

EASMD is a total machine language de- 
velopment package. The editor provides 
functions like FIND, REPLACE, etc. The 
assembler uses standard 6502 mnemon- 
ics, can include multiple files in one assem- 
bly, and can place the object code in 
memory or to a disk file. 

Prices of CP/A with: 

BASIC $ 69.95 

Business BASIC 84.95 

EASMD 69.95 

BASIC + EASMD 109.95 

Business BASIC + EASMD .... 124.95 

Requires 48K HAM and DISK 

Add $3.50 tor shipping and handling in continental USA. 
California residents add 6%. VISA/Master Charge wel- 
come. Personal checks require two weeks to clear. 

SEE YOUR DEALER or ORDER TODAY 



OPTIMIZED SYSTEMS SOFTWARE 
is a product uf 

Shepardson Microsystems, Inc. 

20395 Pacifica Dr.. Suite I08B 

Cupertino, CA 95014 

(408) 257-9900 




Photo 9: With the production of two of the speaker assemblies I have described, we are 
in business. The one wired to the microphone input of the modem should be placed 
under the earpiece of the phone, and the one designated as the modem output speaker 
against the telephone mouthpiece. Dial your favorite computer, place the handset in the 
coupler, and when you see the carrier-detect indicator light, you are ready to go. 



(bought on the surplus market for 
$20.00), purchased from the source I 
listed, or you can make one from 
readily available materials which cost 
virtually nothing. 

Photos 3 thru 9 illustrate the con- 
struction of an acoustic coupler. Both 
the transmitter and receiver use a 
2-inch Radio Shack 8-ohm speaker 
and such "exotic" materials as foam 
pipe insulation, a plastic placemat, 
needlepoint canvas, and rubber 
cement. 

When you are through building the 
coupler, connect it to the modem cir- 
cuit and dial your favorite timeshar- 
ing system. When the telephone con- 
nection has been made and you hear 
the tone, place the handset into the 
coupler. The carrier-detect LED 
should light, and you'll be in 
business. 

If you succeed in building the 
modem and use it to call The Source, 
send me a message describing your 
effort. My user-identification number 
is TCE317. 

Next Month: A simple remote data- 
entry terminal for use in home con- 
trol applications. ■ 



Readers who wish to obtain the 
modem may order the following: 

• a complete kit of 
integrated circuits and 
components as shown in 
figures la and lb, a 
printed-circuit board, 
and directions for 
assembly— $39.95 

• two commercially made 
rubber cushions designed 
to fit 2-inch speakers, for 
use in acoustic couplers 
arid two 2-inch 
speakers — $12. 95 

• this modem is available 
combined with the 
COMM-80 serial/ 
parallel interface (June 
Circuit Cellar) and called 
the "chatter box. " 
Assembled and tested 
with software —$259. 95 

Order these from: 

The MicroMint Inc 
917 Midway 
Woodmere NY 11598 
(516) 374-6793 

Please add $2 for shipping and 
handling. New York residents 
please add 7% sales tax. 



38 August 1980 © BYTE Publications Inc 



Circle 24 on inquiry card. 



m 




r every smarT 
compuTer neeDS an 
SDSYSTems Heart 

We design and manufacture a complete line of in- 
dustry compatible microcomputer boards and kits 
that can serve as the heart of your system. All are S- 
100 Bus compatible and use the Z80 microprocessor. 

MPC-4 — This SD Systems exclusive is a multi port 
controller which uses the Z80 for multi-user opera- 
tions offering four serial RS-232 I/O channels. 

SBC 100/200— A 2.5/4 megahertz range of single 
board computers which are effective standing alone 
or combined with the complete SD board range. 

ExpandoRAM till — For use with 250/200 nanosec- 
ond RAM, these high density boards offer 16 to 64K 
memory; the ExpandoRAM II can achieve RAM ca- 
pacities up to 256K using 64K chips. 

Versafloppy till — A floppy disk controller for up to 
four drives, supporting single/double density and 
single/double-sided disk formats. 

VDB-8024 — A full function visual display board with 
a Z80 controller that adds display capabilities to 
your system. 

Prom 100 — A specialty board of SD Systems which 
allows you to program 2708/2716/2732 proms. 

Z-80 Starter Kit — A low-cost entry into the world of 
microcomputers designed primarily for education 
and experimentation. 



• ■■ \\\ ■'■■'■■■ - 

• V '-AW'-''- : 



\ >*W 





SDSYSTEMS 

RO. Box 28810 • Dallas, Texas 75228 • 214-271-4667 • Telex 6829016 



NOW YOU CAN SAVE $25 PER BOARD* 

when you purchase any SD Systems microcomputer 
board from participating SD Systems dealers listed 
below. *Offer expires 10/31/80 



ADVANCED COMPUTER 
PRODUCTS, INC. 

Irvine CA • 714-558-8813 

ANCRONA 

Culver City CA • 213-6414064 

COMPUTER CITY 

Charlestown MA • 800-343-6652 
or 617-242-3350 

THE COMPUTER MART 

Waltham MA • 617-899-4540 

COMPUTER PRODUCTS 
STORES 

Springfield IL • 217-528-0027 

CUSHMAN ASSOCIATES 

Wilmington DE • 302-995-6733 

DAL-COMP 

Dallas TX- 214-350-6895 



FUTURE ELECTRONICS 

Natick MA -617-237-6340 

JADE COMPUTER 
PRODUCTS 

Hawthorne CA • 800-421-5500 

MINI MICRO MART 

Syracuse NY - 315-422-4467 

PRIORITY ONE 

Sepulveda CA • 800-423-5633 or 
213-894-8171 

8*100 

Clark NJ- 201-382-1318 

Q.T. COMPUTER 
SYSTEMS, INC. 

Lawndale CA • 800-421-5150 
(ex. CA) or 21 3-970-0952 



For complete product information, send for SD Systems' board and kit 
brochure (BK-101). 



Product Review 



The Ohio Scientific CA-15 Universal 
Telephone Interface 



Gregg Williams, Editor 



Imagine the following scenario: a businessman in San 
Francisco calls his office in Boston. The phone rings four 
times, then a metallic voice answers. 

"Hello, " it says, "this is the message service of Morell 
Pharmaceuticals. If you wish to leave your number, 
please type it in using your push-button phone. Thank 
you. " 

Since the man calling is John Morell, the owner, he 
knows he can type in a special access code. He types in 
999 on the Touch Tone phone. The computer on the 
other end of the line recognizes this sequence. 

"Business status, " the metallic voice answers. "Zones 1 
thru 8 secure — no intruders. Zones 1 thru 8 report no fire 
alarms. Do you wish messages?" 

Mr Morell types in 9, which stands for yes. 

"You had three calls. Mr Morse called at 6:04 PM. Ms 
Morell called at 7:40 PM. Unidentified caller, phone 
555-1501, called at 7:51 PM. Do you wish controls?" 

Mr Morell types in another yes. 

"Operation ?" the computer asks. Mr Morell presses the 
buttons for the digits and 2. 

"Office lights on. Time to turn off?" the computer asks. 
Mr Morell presses the buttons 1, 0, 4, and 5, instructing 
the computer to turn the lights off at 10:45 that night. 

"Another command?" Mr Morell types in a 6, which 
stands for no. 

"Thank you. Good night," the computer voice says, 
then hangs up. 

Is this another computer user's fantasy? (After all, we 
know that computers cannot do useful things like start 
coffee in the morning or water the lawn. ) No, the above 
scene is entirely possible. In fact, I have seen a scaled- 
down demonstration similar to the above during a recent 
trip to Ohio Scientific to see its new CA-15 universal 
telephone interface (UTI). 

Description 

The CA-15 universal telephone interface (shown in 
photo 1) is a one-board peripheral device that will fit in 
any Model C8P, C2-8P, C2-OEM, or C3-series Ohio 
Scientific computer. The internal organization of the 



Touch Tone is a registered trademark of the Bell 
Telephone System for its dual-tone, multiple- 
frequency signaling system. 




Photo 1: The CA-15 universal telephone interface board, shown 
with its optional Votrax voice synthesis module. 




Photo 2: Rear panel of an Ohio Scientific C8P computer, show- 
ing connections from the CA-15 universal telephone interface to 
outside components. The board connects to a CBT-type data 
coupler through the DB-15 connector (the small gold-colored 
connector in the center of the back panel). Other connections 
are made through the six phono jacks in the upper right-hand 
comer of the back panel. The jacks, listed in row order from left 
to right, are: cassette-recorder on/off control, phone-line 
monitor output, Votrax output (if used), cassette-player on/ off 
control, cassette-player input, and auxiliary input. 



40 August 1980 © BYTE Publications Inc 







Meet the IMPs. A pair of stylish 3V 2 inch high 
impact printers that will look great on any desk. 



Styled for desk top use, these sleek units stand just 3 1 /2 
inches high, yet the unique fan-cooled printing system 
can knock out 80, 96 or 132 columns of crisp hardcopy 
with continuous throughput of one line per second. 

A winning pair. IMP-1, with friction feed, can make 
multi-copies on plain 8 1 /2 inch wide paper, or on teletype 
rolls. In addition, IMP-2 has tractor feed and full forms 
control, with tractors adjustable from 1 inch to 9 1 /2 inches. 

Interfaces abound. All IMPs have Centronics parallel 
and RS232C/20mA serial inputs as standard equipment. 
But if you need something different, then we make 
interfaces for just about any system — high speed serial, 
Apple, Pet, TRS-80, IEEE 488 .. . 



Versatile, too. 96 ASCII character set is standard. And 
you can select 6 character sizes, even graphics, under 
software control. Options include 2K buffering and 
special character sets. 

Service — a big difference. No other printer 
manufacturer offers Axiom's combination of lowcosf and 
nation-wide service and distribution — in the USA and 
eighteen overseas countries. 

Pssst — the price!!! It's low. $695 for IMP-1. $795 for 
IMP-2. And that's the single unit price. 

Better phone, write or mail the bingo card today! 




Circle 25 on inquiry card. 



5932 San Fernando Road, Glendale, CA 91202 
Tel: (213) 245-9244 • TWX: 910-497-2283 



BYTE August 1980 



41 



COMPUTER 
BUS 



UNIVERSAL TELEPHONE INTERFACE (INSIDE DOTTED LINES) 
I 



DATA /CONTROL INTERFACE 



TAPE PLAYER 
CONTROL 



l_. 



VOTRAX * 



300 BPS 
MODEM 



SOUND 
DETECTOR 



TOUCH-TONE 
DECODER 



DUPLEXER 



AMPLIFIER* 



TAPE 

RECORDER 

CONTROL 



TONE 
DIALER 



PULSE 
DIALER 



SOUND 
MULTI- 
PLEXER 



FAILSAFE 



RING 
DETECTOR I 



PHONE LINE 

CONNECT 

CONTROL 



TAPE 
PLAYER 



SPEAKER 



TAPE 
RECORDER 



AUXILIARY 
DEVICE 



CBT-TYPE DATA 
COUPLER 



Figure 1: Block diagram of the CA-15 universal telephone-interface board. The boxes inside the dotted lines 
are part of the interface board (shown in photo 1). The unshaded boxes are external equipment that must be 
supplied by the user, with the exception of the Votrax module and amplifier {both marked with an asterisk), 
which are optionally supplied with the interface board. 



PHONE LINE 



board is shown in figure 1. 
The CA-15 interface can: 



Initiate either Touch Tone or rotary pulse dial- 
ing of telephone numbers of any length. 
Use Touch Tone dialing to transmit numeric and 
control data. 

Sense a phone line ringing (on an incoming call) 
or a busy signal (on an outgoing call). 
Answer incoming calls and disconnect outgoing 
calls. 

Act as a 300 bits per second (bps) originate-or- 
answer modem. 

Play a prerecorded message from an external 
cassette player onto the phone line. 
Record a voice message onto an external cassette 
recorder. 

Place audio information (eg: computer-generated 
music from a digital-to-analog converter) on the 
phone line from an auxiliary input device. 
Optionally, speak using a computer-controlled 
Votrax speech synthesizer. 



The CA-15 interfaces to the outside world via seven 
output jacks, as shown in photo 2. The board connects to 
a dedicated (ie: not used for any other purposes) 
telephone line through a CBT-type data coupler, which 
can be purchased from Ohio Scientific or rented from the 
telephone company. The data coupler is necessary to 
make a reliable, safe, and legal connection between a 
computer and the telephone line. 

The universal telephone-interface board connects to 
the external data coupler through a DB-15 connector (the 



small gold connector in the center of the C8P rear panel 
shown in photo 2). The remaining six connections are 
made through the two rows of three jacks each in the up- 
per right-hand corner of the computer's backplane. The 
jacks, listed in row order from left to right, are: cassette- 
recorder on/ off control, phone-line-monitor output, 
Votrax output (if used), cassette-player on/off control, 
cassette-player input, and auxiliary input. 

In keeping with Ohio Scientific's "hardware-first" 
orientation, the interface is controlled through examining 
and writing to (PEEKing and POKEing, in BASIC) cer- 
tain memory locations. For example, to dial the three 
digits 6, 0, 3 (after initializing the interface board), we ex- 
ecute the BASIC instructions: 

POKE 63494,189 
POKE 63494,215 
POKE 63494,190 

The documentation supplied with the CA-15 universal 
telephone interface includes complete instructions that 
detail manipulation of the interface through reading and 
writing the appropriate memory locations. 

Commentary 

Coupled to the security and home-control options 
available in the Ohio Scientific line of computers, the 
CA-15 universal telephone interface is the link that ex- 
tends the influence of a computer beyond its immediate 
environment. This extended environment includes any 
point within reach of the existing telephone network. 
With the Ohio Scientific AC-12P wireless remote-control 
option, the CA-15 interface can control home appliances 



42 August 1980 © BYTE Publications Inc 



INTRODUCING HP-OS 

A NEW WORLD OF 

PERSONAL-PROFESSIONAL 

COMPUTATION. 



Imagine the new world 
that would unfold before 
you if you had a powerful, 
portable, completely 
integrated computer sys- 
tem at your personal 
disposal. And at an afford- 
able price. That's exactly 
what Hewlett-Packard has 
just created. 

THE HP-85: 

A PERSONAL 

COMPUTER FOR 

PROFESSIONALS. 

At the lab, on your desk 
or in your study this 
20-pound, self-contained 
system provides pro- 
fessional computing power 
when and where you 
need it. That means no 
more waiting for data 
to be remotely processed 
and returned. 

A COMPLETE 

COMPUTER SYSTEM 

IN ONE SMALL 

PACKAGE. 

You get all this in the 
HP-85: 

Interactive graphics under 
keyboard control. 
16K RAM Memory 
standard. 

Standard typewriter key- 
board with separate 
numeric key pad and eight 
user-definable special 
function keys. 

High resolution CRT display with 
powerful editing capability. 
Built-in thermal printer produces a 
hard copy of the display on command 
Built-in tape cartridge drive. 
Each cartridge provides 217K bytes 
of storage capacity. 
Operating system and BASIC lan- 
guage, permanently stored in ROM. 

A SOPHISTICATED 

COMPUTER AT 
YOUR FINGERTIPS. 

Hewlett-Packard has combined 
these sophisticated capabilities with 
advanced design to give you a 
system that is easy to use yet uncom- 
promised in its power. 

A key to this achievement is 
Hewlett-Packard's choice of BASIC 
for the HP-85 's language. The 




/ 






^ULit&TlT! 




You can enhance the 
system's capability by 
adding powerful HP 
peripherals like a high- 
speed, full-width line 
printer, full-size plotter, or 
flexible disc drives. 

And HP Application 
Pacs offer preprogrammed 
solutions in a wide 
variety of disciplines on 
prerecorded magnetic 
tape cartridges. 

So, when you buy the 
HP-85, you're not just 
buying a computer system, 
you're buying the con- 
fidence that the Hewlett- 
Packard name brings 
and the knowlege that the 
HP-85 can expand with 
your changing needs. 

For the address of your 
nearest HP dealer, CALL 
TOLL-FREE 800-547-3400 
except from Hawaii 
or Alaska. In Oregon, call 
758-1010. For details 
on the HP-85, send the 
attached coupon, or write: 
Hewlett-Packard, 
1000 N.E. Circle Blvd., 
Corvallis, OR 97330, 
Dept. 276C 



HP-85 has more than 150 commands 
and statements to let you solve 
your problems swiftly and easily. 

In addition, sixteen graphic com- 
mands have been added to the 
HP-85's extended BASIC to give you 
easy control of its amazingly 
versatile graphic capabilities. 

DESIGNED FOR TODAY 
AND TOMORROW. 

Whether you're in science, 
engineering, industry or business, 
the HP-85 you need today can 
easily be expanded or customized to 
meet your needs tomorrow. 

You can double RAM capacity to 
32K or expand ROM firmware 
to 80K with optional modules that 
plug right into the HP-85. 



11 



HEWLETT 
PACKARD 



619/26 



HEWLETT-PACKARD 

Di'pl. 276C 

1000 N.E. Circle Blvd. 

Corvallis. OR 97330 

Please send details on HP-85. 



TITLE 

COMPANY- 
ADDRESS- 
CITY 



STATE - 



Circle 26 on inquiry card. 



BYTE August 1980 



43 



Improved! 



mpostmastM^ 



Tomorrow's 
mail system. 

Today. 



One package does it ALL. Teratek's 
Postmaster offers the most powerful and flexible 

mail-management system available for any 

CP/M or compatible derivative capable of running 

CBASIC II, now including Apple II. 



Menu Driven. 

Up to 250K Records Per 

File Name. 

Up to 16 Drives Supported. 

9 Digit Zip Code Supported. 

Batch Entry: Entering names 
and addresses to a mailing 
list is simple. Repeated 
elements of a record need 
only be entered once. 

Powerful Record Extraction: 

Used in conjunction with the 
Optional Reference Field, 

this feature allows simple 
creation of user specified 
"target-files!' 

Dedicated Record Editor: List, 
modify or delete records. 
Allows intact or extracted 
backup of original file. 
Automatic "ID" Field 
Insertion: (optional) Key in a 
name, and a unique 10 char- 
acter record identifier will be 
entered automatically to the 
Reference area. 

Envelopes: Postmaster pre- 
pares single or continuous 
envelopes. 

Mailing Labels: Standard or 
user-specified formats up to 
five across. Any number of 
labels per name. 



mWBBaffig|mmBBSffiffliBB tlSB 



Dealer Inquiries Invited 



Translator Program NAD 
to Postmaster Provided as 
Full Source. 

Form Letters: Supports 
courtesy titles, nicknames, 
single page or continuous 
form. Optional text or saluta- 
tion inserts in any letter. 
Dedicated Record Sorting. 
Attractive Reports: Neat, 
paginated reports on either 
80 or 132 column paper. 
Clear, Complete 
Documentation. 
Quality That's Affordable and 
Available: The Postmaster 
programs are available in a 
variety of 5" and 8" disk for- 
mats (40k of RAM, CP/M and 
CBASIC2 are required). 
Among the formats sup- 
ported are TRS-80, North Star, 
Heath H8 and H89, standard 
8" IBM, Vector MZ and other 
CP/M derivatives capable of 
running CBASIC. 

Sample Data Files Included. 
Powerful Yet Easy to Use. 

All Output Programs Provided 
as Full Source. 

It's terrific! 

We use it ourselves! 

COMPLETE 
PACKAGE: 



$ 150. 

MANUAL 
ALONE: 



Lifeboat Associates 

SOFTWARE 
SUPER- 
MARKET 



(Credited toward 
subsequent purchase) 

*CP/M is a trademark 
of Digital Research 



LIFEBOAT ASSOCIATES «, 

1651 Third Avenue, New York, N.Y. 10028 D (212) 860-0300 D Telex: 220501 



44 August 1980 © BYTE Publications Inc 



from any Touch Tone telephone. (A dial-type telephone 
can also be used if the person called has an external 
device that generates the standard Touch Tones.) 

With the AC-17P home-security option, the CA-15 in- 
terface allows you to remotely determine whether intru- 
sion, fire, or car alarms have been activated. And, with a 
sufficiently sophisticated BASIC program running, you 
can interconnect and control the security and wireless- 
control options from any telephone. 

Other applications that come readily to mind are a 
sophisticated telephone-answering service (such as the 
scenario at the beginning of this review) and a stand- 
alone terminal, which can be used to call up computer 
bulletin boards, time-sharing services, and other remote 
devices. 

The CA-15 universal telephone interface requires three 
power-supply voltages ( + 5 V, +12 V, and —9 V), while 
the popular model C4P computer (and its predecessor, 
the C2-4P) supply only +5 V. Other difficulties include 
the large number of input and output lines the interface 
requires and the limited number of slots in the C4P and 
C2-4P. Because of these problems, the interface cannot be 
used with the above two machines. However, I was told 
that an area of the CA-15 board has been left blank (see 
the bottom center of the interface board in photo 1) for a 
voltage-doubler circuit that would make its use feasible in 
the C4P and C2-4P. C4P or C2-4P owners interested in 
this option should express their interest to Eric Davis at 
Ohio Scientific, 1333 S Chillicothe Rd, Aurora OH 
44202. 

The CA-15 universal telephone interface is available 
through Ohio Scientific dealers for $499, or $799 with the 
Votrax voice module added. A Federal Communica- 
tions Commission (FCC) approved CBT-type telephone 
line isolator is available for $199. Finally, a modified disk 
BASIC called Security BASIC is available for disk-based 
Ohio Scientific machines only. It is a modified Microsoft 
9-digit-precision BASIC with extensions for the wireless 
remote-control, home-security, and telephone-interface 
options; these software extensions replace some of the 
PEEKs and POKEs otherwise used for device control with 
B ASIC-like mnemonic commands. The Security-BASIC 
language system is available for $99. ■ 




Official Flag of Auti-FORTH Programmers 

Circle 27 on inquiry card. 




The MODEL 800 MST is certainly pleasing to look at, but its true beauty lies beneath the surface. A glimpse at its 
features reveals why it is rapidly becoming the most sought after printer in the world . . . 



Four standard interfaces: 

RS-232 (15 baud rates) 

Centronics compatible parallel 

IEEE-488 

20ma current loop 
Six line densities: 64, 72, 80, 96, 120, 132 
100 CPS at all six densities 
Unidirectional or bidirectional printing 
Sixteen horizontal and ten vertical tabs 
Elongated characters in all six densities 
1920 character buffer 
Uses either perforated or roll paper 
Fully adjustable tractors to 9Va" 
Auto self-test 



Up to 10 character fonts 

Standard 96 character ASCII 

User defined character font 

Provision for up to eight additional fonts 
Dot resolution graphics in six densities 
Variable line spacing control from to 64 dots in 
half-dot increments 

Auto form-feed for any form length at any line 
spacing 

Heavy-duty all aluminum chassis 
1 lOvac or 220vac, 50/60Hz. 
100 million character prirlthead 
Measures only 15" wide, 3" high, and 1 1" deep 
Weighs only 15 lbs. 



but maybe its most attractive feature is the price $699.00. 



bo/e_ inc. 



w 



P.O. 

& 



BOX 3548 FULL.. CAL. 98634 / C714) 998-4344 



Product Review 



The Heath H-89 Computer 



Mark Dahmke, 1515 Superior St, Apt 15, Lincoln NE 68521 

The Heath H-89 is Heath Company's latest in their 
rapidly expanding line of desk-top computers. The H-89 
has a number of unique hardware features, and the same 
excellent software support and documentation as the 
original H-8 8080-based system. 

Heath Company is promoting the H-89 as the all-in- 
one computer, which it most certainly is. It is based on 
the Zilog Z80 microprocessor, which makes it upward- 
compatible with all H-8 8080 software. Not only is the 
computer based on the Z80, but the video display ter- 




Photo 1: The Heath H-89, a Z80-based all-in-one personal com- 
puter with built-in 5-inch floppy-disk drive, WH-19 terminal, 
and 16 K bytes of programmable memory (expandable to 48 K 
bytes). The price for the assembled unit is $2295. 



x 1 


Ti'lfll 


- 


r- ,-, --<Vf! 


n 


W\V: 






i 

n 








,: 


/I 


W" 


. , ■ ™ ' , : • J 


f 


^ - 


.&i 


m-ij.m M, >*\ 




^m^^i ; * - /,-./ 


" 


1 


SSk 


my 






_j 



Photo 2: Interior of the Heath H-89 computer. 

46 August 1980 © BYTE Publications Inc 



minal and keyboard subsystem also contains a Z80. 

The processor board Z80 runs at 2.048 MHz — slightly 
faster than an 8080 at 2 MHz, but not at the 4 MHz max- 
imum possible with a Z80. Up to 48 K bytes of main 
memory may be plugged into sockets directly on the pro- 
cessor board, as well as up to six expansion cards on 
twenty-five pin connectors. The processor board also has 
single-step and full interrupt logic, a serial RS-232 port 
that connects to the terminal board, and sockets for three 
2708 EPROMs (erasable programmable read-only 
memories). 

The terminal board consists of a Z80, a 6845 video con- 
troller chip, two read-only memories, two 2112-2 pro- 
grammable memory components, an S740 keyboard 
encoder circuit, and an 8250 UART (universal asyn- 
chronous receiver/transmitter) for RS-232 communica- 
tions. The terminal has a 12-inch video screen that 
displays twenty-four lines of eighty 5-by-7 dot-matrix 
characters. The twenty-fifth line is accessible under soft- 
ware control for special applications. Lowercase 
descenders and thirty-three 8-by-10 dot graphics 
characters are also provided. 

A full keyboard with repeat key (this repeats any key 
pressed), eight user-definable function keys (see table 1), 
and a separate numeric keypad are standard on the H-89. 

The special function keys generally send out a series of 
characters such as ESC H for cursor home, ESC E for 
erase screen, and so on. Although Heath has its own set 
of escape functions, the terminal may be placed in the 
ANSI (American National Standards Institute) mode for 
a standardized set of the same functions. The numeric 
keypad actually has three possible modes: the unshifted 
numeric mode (normal), the keypad shifted mode, and 
the alternate keypad mode. Table 2 shows the keycodes 
for each mode. A complete list of escape sequences is 
shown in table 3. 

The ESC r X sequence allows the user to set the data 
rate from 110 to 9600 bits per second. For example, ESC r 
C sets the data rate to 300 bits per second. 

Another nice feature is the special twenty-fifth line of 
the screen. This line is separate from the other twenty- 
four and will not scroll with the rest of the screen. The 
line may be enabled by sending ESC x 1 from either the 
computer or the keyboard. After enabling the twenty- 
fifth line, the cursor must be positioned somewhere in the 
line before writing characters using the direct cursor 
addressing sequence: ESC Y (line number) (column 
number) where the line and column numbers are sent as 
two ASCII characters after the ESC Y. In this case, the 
line number is 25 + 31 (31 must be added to the actual 
line and column number values) which is equal to 56 or 
"8" in ASCII codes. The column number (1 to 80) may 
range from 32 (ie: 1 + 31) to 111. To position the cursor 

Circle 28 on inquiry card. ^^^- 



MEMORY EXPANSION FOR TRS-80 

All you have to remember is to plug it in 



Memory expansion. It's a field packed with 
intriguing theories. For instance, it has been 
suggested that the memory areas of the 
human brain are transferable from one body 
to another, like transplanted kidneys. In man 
or machine, a larger memory is always a 
welcome acquisition. 

If you are interested in expanding your 
TRS-80 memory without shelling out dollars 
for a full blown expansion interface, we have 
just the solution. 

Introducing the MT-32. Our new, brilliantly 
designed Printer/Memory expansion module 
for the TRS-80. This unit will add 16K or 32K 
of dynamic RAM to your basic 16K machine. 
The module also contains circuitry to drive 
Microtek's MT-80P dot matrix printer, or any 
other Centronics-compatible printer. 

No hardware modification to your TRS-80 is 
required. Just plug into your bus connector 
and you are ready to go. 

All Microtek products are covered by a one 
year warranty. 



TRS-80 is a Registered Trademark of Tandy Corp. 



Four configurations are available: 



Without RAM in kit form 
(MT-32K @ $79.50) 



Without RAM assembled and tested 
(MT-32A @ $99.50) 



With 16K RAM assembled and tested 
(MT-32B @ $159.50) 



With 32K RAM assembled and tested 
(MT- 32C @ $199.50) 



Available from Microtek 

or your nearest computer dealer. 




MICROTEK^ 



9514 Chesapeake Drive 
San Diego, CA 92123 
Tel. (714) 278-0633 
TWX 910-335-1269 



MHHORY TRANSPLANT 






Key 


Heath Mode 


ANSI Mode 


F1 


ESCS 


ESC OS 


F2 


ESCT 


ESCOT 


F3 


ESC U 


ESCOU 


F4 


ESCV 


ESCO V 


BLUE 


ESC P 


ESCO P 


RED 


ESCQ 


ESCOQ 


GRAY 


ESCR 


ESCO R 


Table 1: Special function keys on 


the Heath H-89 computer. 



Unshifted Shifted 


Alternate 


Key Key 


Keypad Mode 





ESC? p 


1 ESC L 


ESC?q 


2 ESC B 


ESC? r 


3 ESC M 


ESC? s 


4 ESC D 


ESC? t 


5 ESC H 


ESC? u 


6 ESCC 


ESC? v 


7 ESC @ 


ESC? w 


8 ESC A 


ESC?x 


9 ESCN 


ESC?y 




ESC?n 


ENTER RETURN 


ESC? M 


Table 2: H-89 numeric keypad functions. 





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in column 1 of line 25, the following sequence would be 
entered via the keyboard or sent from the computer: ESC 
"Y" "8" " ". If the sequence is sent from the keyboard, it 
is necessary to look up the character equivalents for each 
value (as above), but if the terminal is driven from a pro- 
gram in BASIC, the process is much simpler: 

PRINT CHR$(27); "Y"; CHR$(56); CHR$(32); 

Note that the CHR$(27) causes the ASCII "ESCAPE" 
code to be sent; 56 and 32 are the line and column 
numbers, added to 31. The CHR$ function converts the 
decimal code number into the corresponding character. 

MTR-88 Monitor Program 

The H-89 comes with a monitor program in program- 
mable read-only memory that allows the user to operate 
at machine level or use the system without disk drives (or 
tape, for that matter). The MTR-88 cassette I/O func- 
tions are compatible with the cassette entry points in the 
PAM-8 front-panel monitor of the H-8, so software writ- 
ten for the H-8 will execute correctly on the H-89. 

The monitor supports the following commands: 



Boof 


Load HDOS from disk. 


Dump 


Dump a program to cassette tape 


Go 


Execute a program at the given 




address. 


Load 


Load a program from cassette 




tape. 


Program Counter 


Set the program counter address 




(prior to entering the Go com- 




mand). 


Substitute 


Inspect or change memory loca- 




tions. 



The load and dump commands are set up to work with 
the H-88-5 cassette interface board. MTR-88 also main- 
tains a tick counter in memory. The counter is a 2-byte 
field at memory addresses 040.033 and 040.034 (in split 
octal notation) that is incremented by 1 every 2 ms as 
long as interrupts are enabled. It is possible to assign 
interrupt vectors for special applications (as with all 
Heath software) by changing the addresses in the bottom 
64 bytes of memory. 

HDOS Disk Operating System 

HDOS (Heath Disk Operating System) is a comprehen- 
sive disk-management package. HDOS allows the user to 
create, manipulate, and display the contents of disk files 
and the disk directory. Other commands allow the user 
to display disk statistics (ie: usage, remaining space, 
errors) and to set device options such as console/printer 
data rate, whether or not a back-space cursor function is 
available on the terminal in use, uppercase or 
upper/lowercase mode, tabs, console width, and so on. 
HDOS provides "device drivers," special subroutines 
which perform all necessary initialization and housekeep- 
ing functions for each peripheral interface — console, line 
printer, alternate console, and so on. The device drivers 
may be called by the user's program, saving the user the 
effort of writing device interface routines. 



48 August 1980 © BYTE Publications Inc 



Circle 29 on inquiry card. 



Circle 30 on inquiry card. 




Icrosoft 
Z-80 SoftCard. 

Leading a Whole 
New Lineup for 

Your Apple II. 

Plug the new Microsoft Z-80 SoftCard tnt 
Apple II™ and start using all of the system and applicati. 
software written for 2-80 based computers. Software that 
you could never use before on your Apple II. 

The SoftCard actually contains a Z-80 processor and 
lets you switch between the Apple's 6502 and the Z-80 with 
simple commands, so you can use software written for 
either processor. 

Starting with Two Software Standards. Versatile 
CP/M," the most widely used microcomputer operating 
system ever, is included on diskette in the SoftCard 
package, ready to run on your Apple II 

You get Microsoft's 5.0 BASIC too, the most powerful 
version to date of our famous BASIC interpreter. 

PRINT USING, 16-digit precision, CALL, and CHAIN 
and COMMON are just some of the major BASIC features 
you'll add. Applesoft's graphics extensions are still included. 

More Power Down the Line. You can get even more 
programming power and versatility by adding Microsoft's 
FORTRAN, COBOL, BASIC Compiler and Assembly 
Language Development System. All are available 
separately to run with the SoftCard system. 

And the whole host of CP/M-based business, scientific 
and educational applications can be easily transferred to 
your Apple with SoftCard. 

The Microsoft Z-80 SoftCard is compatible with most 
every Apple product from the Apple II to the Apple II Plus, 
Language Card and peripherals. Independent peripherals 
for the Apple are supported>as well. The SoftCard package 
requires a system with 48K and a disk drive. 

Line up a SoftCard demonstration at your Microsoft 
Consumer Products dealer today. They'll be glad to show 
you how the Z-80 SoftCard and your Apple computer 
combine to form a system that can't be beat for either 
practicality or pure pleasure by any personal computer 
available today. Or give us a call, 206/454-1315, for 
more information. 

But act quickly. At the low price of $349 for SoftCard, 
CP/M, Microsoft BASIC and complete documentation, you 
may have to stand in line to get one! 

'"Apple II is a trademark of Apple Computer, Inc. 
" CP/M Is a registered trademark of Digital Research. 




CONSUMER PRODUCTS 

10800 Northeast Eighth, Suite 507 
Bellevue, WA 98004 
(206)454-1315 







All devices on the H-89 have been assigned device 
names. Table 4 lists all devices. For example, to list a file 
on the printer, the command 

COPY LP: = SYO:FNAME.EXT 

is used, where LP: is the destination, and FNAME.EXT is 
the disk file on device SYO: to be listed. 



The H-89, Heath's all-in-one computer, 
has a number of unique hardware 
features and the same excellent soft- 
ware support and documentation as the 
original H-8 system. 



ESC H 


Cursor home 


ESCC 


Cursor forward (right) 


ESCD 


Cursor backward (left) 


ESC B 


Cursor down 


ESC A 


Cursor up 


ESC 1 


Reverse index 


ESCn 


Cursor position report 


ESCj 


Save cursor position 


ESCk 


Set cursor to previously saved position 


ESC Y 


Direct cursor addressing 


ESCE 


Clear display (also shift erase) 


ESCb 


Erase beginning of display 


ESCJ 


Erase to end of page 


ESCI 


Erase entire line 


ESCo 


Erase beginning of line 


ESCK 


Erase to end of line 


ESCL 


Insert line 


ESC M 


Delete line 


ESCN 


Delete character 


ESC @ 


Enter insert character mode 


ESCO 


Exit insert character mode 


ESCz 


Reset to power-up configuration 


ESC r Bn 


Modify data rate (Bn is a character to select data 




rates from 110 to 9600 bps.) 


ESC x Ps 


Set mode: (select Ps from:) 




1 = Enable twenty-fifth line 




2 = No key click 




3 = Hold screen mode 




4 = Block cursor 




5 = Cursor off 




6 = Keypad shifted 




7 = Alternate keypad mode 




8 = Auto line feed on receipt of carriage 




return 




9 = Auto carriage return on receipt of line 




feed 


ESC y Ps 


Reset mode(s): (same as set modes listed above) 


ESC < 


Enter ANSI escape-sequence mode 


ESC[ 


Enter hold screen mode 


ESC \ 


Exit hold screen mode 


ESCp 


Enter reverse video mode 


ESCq 


Exit reverse video mode 


ESCF 


Enter graphics mode 


ESCG 


Exit graphics mode 


ESCt 


Enter keypad shifted mode 


ESCu 


Exit keypad shifted mode 


ESC = 


Enter alternate keypad mode 


ESC > 


Exit alternate keypad mode 


ESC } 


Keyboard disabled 


ESC{ 


Keyboard enabled 


ESCv 


Wrap around at end of line 


ESC w 


Discard at end of line 


ESCZ 


Identify as DEC VT52 terminal 


ESC] 


Transmit twenty-fifth line 


ESC# 


Transmit page 


Table 3: 


H-89 escape sequences. 



SYO: 

SY1: 

TT: 

AT: 

LP: 

ND: 

Table 4: 


System disk drive #0 

System disk drive #1 (optional) 

Console device 

Alternate terminal (optional) 

Line printer 

Null device (This eats up characters sent to it.) 

H-89 device assignments in HDOS. 



The two directory-oriented devices are SYO: and SYl: . 
On these devices (ie: disks), the directory keeps track of 
what files exist and where they are. Each file can have an 
eight-character name with a three-character extension. 
The extension is useful when keeping track of a number 
of related files. For example: 

MYPROG.ASM 
MYPROG.LST 
MYPROG.ABS 

Here the .ASM indicates that the first file is the assembler 
source of MYPROG entered via the text editor. The .LST 
file is the listing output of the assembler, and .ABS is the 
object code resulting from the assembler run. 

HDOS Utilities 

HDOS also comes with a number of useful utility pro- 
grams: 

PIP (peripheral interchange program) 

A generalized disk-file 
maintenance program. 

ONECOPY A program that allows the user 
with only one disk drive to copy 
files from one disk to another. 

SET A very useful program that 

allows the user to redefine device 
driver configurations. Table 5 
lists all options of the SET com- 
mand. 

STAT Displays system performance, 

number of disk errors, etc. 

FLAGS Sets disk-file flags to write-protect 

a file, to suppress normal listing 
and copying of a file, and 
(optionally) to lock the file 
against further flag changes. 

DBUG 

The Heath console debug program allows the user to 
enter and debug machine-language programs from the 
console. DBUG will perform the following functions: 

• Display and alter contents of any memory location. 

• Display and alter contents of any 8080 processor 
register. 

• Single step through a program. 

• Execute a program. 

• Set breakpoints in a program. 

• Load or dump user programs to or from a device 
(eg: tape or disk). 

Note that DBUG supports only the 8080 register set, not 
the extra registers in the Z80. Also, DBUG does not have 
a disassembler feature. 



50 August 1980 © BYTE Publications Inc 




BRAIN 



Once in a great while someone comes along 
with a simple improvement for an already great 
product. Take our SuperBrain, for example. Really a 
simple concept. A high-powered, low cost micro- 
computer packaged in an attractive desk top 
cabinet. So how do you improve on that? 

WE DID IT... 

It wasn't enough that our SuperBrain had 
such standard features as twin double density 
5%" drives with over 300,000 bytes of disk 
storage. A full 32K of dynamic RAM - expandable 
to 64K in seconds. A CP/M* Disk Operating 
System which assures compatibility to literally 
hundreds of application packages presently availa- 
ble. A crisp, 12" non-glare screen with a full 24 
line by 80 column display. A full ASCII keyboard 
with a separate keypad and individual cursor 
control keys. Twin RS232C serial ports for fast 
and easy connection to a modem and/or a printer. 
And, dual Z80 processors which operate at 4 MHZ 
to insure lightning-fast program execution. No, it 
wasn't enough. So we made it better. 

ANNOUNCING SUPERBRAIN QD... 

Our new QD model has all of the features of 
our phenomenally popular SuperBrain with the 
addition of double-sided disk drives and an extra 
32K of dynamic RAM. So, for only a modest in- 
crease in price, you can order your next SuperBrain 
with more than twice the disk and memory storage 
capability. But, best of all, the new QD model has 
the same tough, rugged construction and 
exceptional quality that made our SuperBrain 
such a success. 





HOW DID WE DO IT? 

The secret of SuperBrain QD's incredible disk 
storage lies within our new double-density double- 
sided disk drives. A total of nearly 720,000 bytes 
of data are formatted on two specially designed 
5%" drives. And that's more than enough to get 
you started with most serious small business 
applications. And SuperBrain QD's standard 64K of 
dynamic RAM will handle even the most complicat- 
ed programming tasks. 

Of course, if you're into megabytes instead of 
kilobytes, you may think neither SuperBrain is right 
for you. Not so! Intertec offers 20-96 megabytes of 
hard-disk storage which connects in seconds to 
either the SuperBrain or SuperBrain QD. So, your 
original investment is always protected. As you 
grow. No matter how much your needs expand. 



BUT IS IT RELIABLE? 

Our best salesmen are our present users. Not 
only have SuperBrain users been impressed with 
the inherent reliability of the system, they tell us 
that no other microcomputer system available 
today offers such a unique modular design con- 
cept. Just about the only tool required to easily 



maintain the system is a common screwdriver. And 
Intertec's total commitment to product service and 
customer support, with service outlets in most 
major cities, insures your original investment will 
be a valuable one for many years to come. 

THE DECISION IS YOURS. 

Whether your next SuperBrain is a regular 
model or our QD version, you will have the 
satisfaction of knowing you purchased what is 
becoming one of the world's most popular micro- 
computer systems. And regardless of which model 
you choose, you'll probably never outgrow it be- 
cause you can keep expanding it. 

So, call or write us today for more infor- 
mation. Intertec systems are distributed worldwide 
and may be available in your area now. 

Circle 31 on inquiry card. 



3 



, NTE3TEC 

Cdata 

= SYSTEMS. 



2300 Broad River Rd„ Columbia, SC 29210 
(803) 798-9100 TWX: 810-666-2115 




'Registered uaoemark of Digital Hesearch. inc 



The Text Editor 

The Heath Text Editor is used to enter and edit 
assembly and BASIC programs, as well as to create and 
edit reports, letters, and manuscripts. 

EDIT uses all available memory in the system as a text 
buffer. When the buffer is full, all or part of it may be 
transferred to a disk file. This allows the user to work on 
files in size up to the limit that will fit on disk. EDIT has a 
very unusual command format: 



< range > <verb> < qualifier string > 
< parameters > 



< option > 



Range defines the buffer lines the command is to operate 
on. Characters to indicate certain lines are as follows: 



t 
$ 

+ 



+ 'string' 
— 'string' 



Defines the first line of the buffer. 
Defines the last line of the buffer. 
Followed by a decimal number, refers 
to the nth line past the current line 
pointer. 

Followed by a decimal number, refers 
to the nth line preceding the current 
line pointer. 

The first line in the buffer which con- 
tains the 'string' after the current line. 
The first line in the buffer which con- 
tains the 'string' preceding the current 
line pointer. 



Multiple line ranges can be specified by using two of 
the above range expressions in sequence with a comma 
between them. A blank preceding a verb will cause the 
command to operate on the entire buffer. An equals sign 
reuses the range of the last command. 

The verb specifies the action to be taken by the editor. 
Examples are: Print, Replace, Delete, Read, Write, Use, 
Search, Bye, and so on. 

The qualifier string is a further restraint on the range 
expression and is optional. For example, it is possible to 
operate on only those lines that contain a phrase or string 
of characters. If the phrase is entered in single quotes in 
the qualifier string field, only those lines containing the 
specified string will be affected. 

The option field determines if the current line is to be 
displayed before it has been modified, after it has been 
modified, or both. Use of this field is optional. 

The parameter field is a special field used to direct disk 
I/O actions of the editor. 

This is the most difficult editor I have ever tried to 
work with. Even after carefully reading the manual and 
spending a great deal of time learning how to use it, it is 
incredibly frustrating. The range and other fields are 
unconventional and require some getting used to. When 
writing programs in BASIC, it is far easier to use the line 
entry and edit commands in the BASIC interpreter. Try- 
ing to write assembler programs with this editor is nearly 
impossible. 

Considering all the excellent software and hardware 
documentation and support of the H-89, and the power- 
ful intelligent terminal features for full-screen editing, it 



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SORCERER Hun 



TH£ AMAZING 

The SORCERER is a Z80 CPU based micro computer inlernally expandable 
lo 4BK 4K ROM resident monllor. I/O connector for S-100 expansion. 
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and lower case), plus standard graphic symbols User may define up lo 
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key numeric Input pad 

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Phone orders invited, using credit cards. Or send cashiers 
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3% ($5.00 Minimum) for handling, shipping (air service) and 
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California residents add 6% sales tax. All equipment is in 
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6363 EL CAJON BLVD., SUITE 205, 
SAN DIEGO, CA. 93115 • (714) 579-0330 




52 August 1980 © BYTE Publications Inc 



Circle 32 on inquiry card. 



Circle 33 on inquiry card. 



26 MEGABYTES 




Suddenly, S-100 microcomputer systems can easily handle 100 million 
bytes. Because Morrow Designs™ now offers the first 26 megabyte hard disk 
memory for S-100 systems-the DISCUS M26™ Hard Disk System. 

It has 26 megabytes of useable memory (29 megabytes 
unformatted). And ifs expandable to 104 megabytes. 

The DISCUS M26™ system is delivered complete- 
a 26 megabyte hard disk drive, controller, cables and operating system-for 
just $4995. Up to three additional drives can be added, $4495 apiece. 

The DISCUS M26™ system features the Shugart SA4008 
Winchester-type sealed media hard disk drive, in a handsome metal cabinet 
with fan and power supply. 

The single-board S-100 controller incorporates intelli- 
gence to supervise all data transfers, communicating with the CPU via 
three I/O ports (command, status, and data). The controller has the ability to 
generate interrupts at the completion of each command to increase system 
throughput. There is a 512 byte sector buffer on-board. And each sector can be 
individually write-protected for data base security. 

The operating system furnished with DISCUS M26™ 
systems is the widely accepted CP/M* 2.0. 

See the biggest, most cost-efficient memory ever intro- 
duced for S-100 systems, now at your local computer shop. If unavailable 
locally, write Morrow Designs,™ 5221 Central Avenue, Richmond, CA 948041 
Or call (415) 524-2101, weekdays 10-5 Pacific Time. 

'CP/M is a trademark of Digital Research. 



Q /MORROW DESIGNS™ 

Thinker Tbys 



SETVER 
SET HELP 


prints the version number of the SET program, 
gives information on the SET command. 


SET TT: HELP gives information on the SET command for a 
particular device; TT: in this case. 


SET TT: 




Option 


Description 


NOBKS 
BKS 


uses the back-slash character for errors, 
allows back-spacing to correct typing errors. 


BKM 
NOBKM 


causes back-space (control-H) to be treated as 

a delete. 

lets HDOS receive the back-space character. 


MLI 
NOMLI 


maps lowercase input to uppercase, 
allows lowercase input to HDOS. 


MLO 
NOMLO 


maps lowercase output to uppercase, 
allows lowercase output from HDOS. 


NOTAB 
TAB 


HDOS expands TAB (control-l). 
lets terminal expand TABs (faster). 


2SB 
1SB 


uses 2 stop bits (universal), 
uses 1 stop bit (normal). 


WIDTH n 


sets console width to n characters, 80 is 
default. 


FILLc n 


sets c as a character that needs n fill 
characters following it; for slow hardcopy ter- 
minals. 


SET LP: 




6LPI 
8LPI 


sets the H-14 printer for six lines per inch, 
sets the H-14 printer for eight lines per inch. 


PAGE n 
PORTn 
WIDTH m,n 
BAUD n 


sets the number of lines per page to n. 
sets the port address for LP: to n. 
sets the width control switch position 
sets the data rate for LP: 


SET AT: 


same as for TT: 


SET SY: 




STEP n 


sets the step time between tracks on the disk 
drive. (The TEST command is used to deter- 
mine the value of n.) 


Table 5: SET command options. 



REPLACE "fname" 
CNTRL iexpl ,iexp2 



FREE 

FREEZE "fname" 

UNFREEZE "fname" 
LOCK 



UNLOCK 
UNSAVE "fname" 



replaces "fname" with current pro- 
gram, if it exists; works like SAVE if 
the file doesn't exist. 
CNTRL sets a GOSUB to line iexp2 
when a CTL-B is typed. 
CNTRL 1 sets iexp2 digits before ex- 
ponential format is used. 
CNTRL 2 controls the H-8 front panel. 
Does nothing on the H-89. 
CNTRL 3 sets the width of a print 
zone to iexp2 columns. 
CNTRL 4 controls the state of the 
HDOS system overlay. iexp2 = 0, 
swap overlay. iexp2 = 1 , keep overlay 
in memory. 

displays the amount of memory 
assigned to tables and program text, 
saves BASIC interpreter, current pro- 
gram, and data values on the file 
"fname". 

reloads the file saved with a FREEZE 
command. 

protects the program by preventing 
execution of BUILD, BYE, CHAIN, 
UNFREEZE, DELETE, RUN, 
SCRATCH, and CLEAR commands, 
reverses a LOCK command, 
deletes the file "fname" from disk. 



Table 6: Extended Benton Harbor BASIC commands not 
found in other versions of BASIC. 



seems incongruous that this system should have such a 
difficult editor to work with. 

The Assembler 

The Heath Assembler is a very straightforward, 
absolute 8080 assembler (not Z80) with most of the stan- 
dard assembler directives (ie: DB, DS, DW, END, EQU, 
ORG, SET, TITLE). The XTEXT directive is used to 
include whole disk files of assembler text into a program. 
This is convenient if there are some standard symbols or 
memory addresses that are to be incorporated into every 
assembler program, such as HDOS definitions. Also, 
useful subroutines may be included in this way. This 
feature may be used as a macro-instruction library facili- 
ty, because the assembler does not allow macro- 



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54 August 1980 © BYTE Publications Inc 



Circle 34 on inquiry card. 



Now you can multiply your 

computing power as you grow. 




Geof 

Director of Systems Development 

"At ADDS, we've just designed a unique computer 
family that can take you all the way from small to big. 

"We call it ADDS Multi vision ™-a trio of stacking, 
CP/M®-compatible computers that lets you multiply 
computing power as needed. Without a change in 
operating system or programming languages. Without 
costly conversion. It works like this: 

"MULTMSION 1 (top module) is a get-started 
computer with 5 MHz processor, 64K bytes of RAM 
and mini disk storage capacity of 700K bytes. It lists 
for $3,785 without terminal. 

"MULTMSION 2 (top and bottom modules) pro- 
vides 5M or 10M bytes of additional hard-disk storage. 
Priced thousands less than other hard-disk systems, 
it lists for $7,995 with 5M bytes of disk. 

"MULTMSION 3 (entire stack) tops off the line, 
giving you a multi-user system with up to 256K bytes 
of RAM that supports up to four display terminals 
simultaneously. 

"We even offer an ADDS-developed package that 
lets you use Multivision as a word processor. 

"Before you decide upon any small computer, • 
look into ADDS Multivision. For years we've been the 
largest supplier of display terminals to computer 
giants. Now we're making a system for you." 

For information write: Systems Division, Applied 
Digital Data Systems Inc., 100 Marcus Boulevard, 
Hauppauge, N.Y 11787. Dealer inquiries invited. 

CP/M is a registered trademark of Digital Research, Inc. 



Circle 35 on inquiry card. 



BYTE August 1980 55 



instruction definitions. A file comes with HDOS called 
HDOS.ACM. It contains standard HDOS system-call 
symbols for easily interfacing a user-written program 
with HDOS and the device drivers. 

Extended Benton Harbor BASIC 

Extended Benton Harbor BASIC (herein referred to as 
EBH BASIC) is Heath's own version of BASIC. It is an 
extension of Dartmouth BASIC with some unique 
features. One of the first differences I noticed was the 
command that initiates automatic line numbering while 
entering programs. In most versions of BASIC it is called 
AUTO, but in EBH BASIC it is BUILD. The BUILD com- 
mand works exactly like AUTO. Another important dif- 
ference is the lack of a RUN "FNAME" command. If 
the user wishes to execute a program that is on disk as the 
file "FNAME", the following must be entered: 

OLD "FNAME" 
RUN 

To clear the machine of program and data, the com- 
mand is SCRATCH, not NEW as in most versions of 
BASIC. 

EBH BASIC has some unique and useful commands. 
(Table 6 lists these special commands and their 
functions.) But it is not without its problems. Even the 
most insignificant of syntax errors, such as leaving out a 
comma or right parenthesis, causes EBH BASIC to 
display a simple SYNTAX ERROR message. Unfor- 



tunately since it has to access a disk file called ERROR- 
MSG.SYS to get the text of the error message, the user is 
forced to wait several seconds to find out what he or she 
probably already knows. The philosophy of storing 
error-message text on disk to save space in memory is a 
useful one, but in this case it severely hampers develop- 
ment of programs. The best approach would be to have 
the most frequently occurring error messages in memory 
and then access the disk for the remainder. 

Microsoft BASIC 

Microsoft BASIC is widely used and is very stan- 
dardized. I will not spend time describing its features. 

The Heath implementation of Microsoft BASIC does 
have one significant fault; when a program is loaded 
from disk, the disk read head is raised and lowered for 
each and every sector of the file. This produces an annoy- 
ing banging sound that seems to go on forever. It is also 
bad for the drive mechanism and will contribute to the 
wear and tear of the unit. 

Conclusions 

The H-89 has flexibility and does not require the user 
to understand anything about the hardware to take full 
advantage of all the features. One important point 
remains: after all the HDOS operating system utilities are 
put on a single 5-inch floppy disk, there is very little 
room for any large user programs. To make the system 
really useful, a second disk drive is a necessity. If the 
H-89 were to be used in a business with a really large data 
base, the data would be a tight fit even with two drives. ■ 



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disassembly of instructions! ! ! 
Directory Catalog System (XDIR) 

Build directory of directories!! Sorts by disk or by program. 
Abbreviated or full form — full form includes dates of creation 

and last update, and other directory data. 
Wild card select options with masks. Build consolidated 

directory of all GL#?/BAS files. Select on filename and extension. 
Save or load XDIR catalog files. 
Concatenate new data with loaded file. 
Extended Copy (XCOPY) 

Copies multiple files with a single command using masked select 
options! Source disk may be non-operating system disk. Single 
drive capability. Recover bad files — invalid sectors Itemized but 
copy continues. 

Merge files with or without replacement. 
Superzap (SZAP) 

Display or print and modify standard TRSDOS diskette track and 
sector data. Full screen edit mode. Automatic repeat scan and 
print. Copy disk sectors — any number of sectors to same or 
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Automatic repair of HIT tables! List and flag directory errors. 

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56 August 1980 © BYTE Publications Inc Circle 36 on inquiry card. Circle 37 on inquiry card. ™^^ 



MOD II BASIC CROSS REFERENCE UTILITY 

SEEK and FIND functions for: 

Variables, Line Numbers, Strings, Keywords 

'All' options available for line numbers and variables. 

Load from BASIC - Cal I with <CTRL> R 

Output to screen or printer. 

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Full MATRIX functions — 30 BASIC commands! 

50 more STRING functions as BASIC commands! 

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co BUSINESS (Requires Infinite BASIC) $29.95 
Automatic printer pagination. Packed decimal arithmetic - 127 digit 

accuracy. Binary array searches. Hash code. 
COMPROC Command Processor for Disk Systems $19.95 
Auto your disk to perform any sequence of commands. 
GSF (Specify 16, 32 or 48K Memory) $24.95 
18 machine language routines including RACET sorts. 

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DSM for Mod I (Minimum 32K, 2-drives) $75 on Disk 
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H-19 Professional 
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You'll be 
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after building 
one of these. 



HiiiiiHiimiivmimuiiHVWM w.iA.', l\.v\ 



H-8 Personal 
Computer with Dual 
Floppy Disk Storage 




H-11A 16-Bit 
Computer with Dual 
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H-89 All-ln-One 

Computer with 

Floppy Disk Storage 



' in knowledge 

Once you build your own computer, you'll 
know it inside out. You'll know how to 
make it work for you, how to make it grow 
as your skills grow. 

Richer in savings 

Build-it-yourself kits cost less - about 30% 
less than comparable assembled comput- 
ers. And you'll probably never need to pay 
someone for service because no one will 
know your computer better than you. 

Is it hard? 

Not at all. Heath makes it simple with easy- 
to-assemble designs and with step-by-step 
manuals that guide you from unpacking to 
final plug-in. And a Heathkit helping hand 
is always just a phone call away. 




H-14 Serial Printer 



Innovative software 

Heath offers you innovative programs for 
running your home or business, and excit- 
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Heath User's Croup (HUG) will share with 
you a library of over 500 programs to make 
your computer serve you in ways you 
never imagined. 

Complete hardware 

Choose from three computer systems: 
The H89 All-ln-One Computer gives you 
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The flexible H8 gives you the freedom to 
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actly the system you require. 
And the powerful H11A gives you 16-bit 



Self-Instruction for Assembly 
and BASIC Programming 



power for your most complex programs. 
The Heathkit line includes video terminals, 
matrix and letter-quality printers and a 
complete selection of accessories. You'll 
even find award-winning self-instruction 
packages to teach yourself programming 
in BASIC or Assembly. 

FREE 

CATALO 

It's all in the 

new 104-page 

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along with nearly 400 electronic kits for 

your home, work or pleasure. Send for 

your free catalog today, or pick one up at 

your Heathkit Electronic Center.* 







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'Visit your Heathkit Electronic Center In the U.S. or Canada where Heathkit Products are 
displayed, sold and serviced. See your white pages for the location nearest you. Heathkit 
Electronic Centers are units of Veritechnology Electronics Corporation in the U.S. 



Write to Heath Company, Dept. 334-686, Benton Harbor, Ml 49022 
(in Canada write Heath Company, 1480 Dundas St E., Mississauga, Ont. L4X 2R7) 



CP-186 



The Hard-Disk Explosion 

High-Powered Mass Storage for Your Personal 

Computer 



Tom Manuel 

1208 Apollo Way, Suite 502 

Sunnyvale CA 94086 



High-performance, high-quality, 
and large-capacity hard-disk drives 
are now a low-cost reality for your 
personal-computer system. Most 
hard disks use Winchester media, 
head technology, and other modern 
techniques to achieve high density 
and high performance in a small 
space. One side effect is low power 
consumption. Some of the drives suit- 
able for personal computers use the 
older 14-inch standard diameter plat- 
ters. Many new drives use one of two 



new small sizes — 200 mm (7.87 inch) 
or 210 mm (8.27 inch) diameter — and 
one new drive uses 130 mm (5.12 
inch) platters. Even so, their data 
capacities are significantly larger than 
floppy-disk drives of the same ap- 
proximate size. 

The latest disk drives can be divid- 
ed into two general categories: 

• low-cost, relatively low- 
performance drives that will 
eventually replace floppy-disk 




Photo 1: The Memorex Model 101 hard-disk drive. (Photo courtesy of Memorex.) 

58 Augusl 1980 © BYTE Publications Inc 



drives, especially where multiple 
drives would normally be neces- 
sary to obtain enough storage. 
For example, instead of adding 
more floppy drives to increase 
the storage capacity of a system, 
one set of dual floppy-disk drives 
might be replaced with an 8-inch 
hard-disk drive that fits in the 
same space. This improves the 
storage capacity and system per- 
formance dramatically. These 
low-end disk products will com- 
pete on a cost-per-drive basis. 
• high-capacity, top-performance 
drives that must compete on a 
cost-per-byte basis. The 8-inch or 
smaller versions will likely (at 
least at first) be more costly per 
byte than the 14-inch models. 
However, their advantages of 
small size, light weight, low 
noise, and low power re- 
quirements make them very at- 
tractive for desktop and personal 
computers as well as small 
business systems. 

The Winchester disk-drive tech- 
nology developed by IBM provided 
expensive, large-capacity, high-per- 
formance, and low cost-per-byte disk 
subsystems (ie: the IBM 3350 and 
3370 disk-drive systems) for large, ex- 
pensive computer systems. This 
technology and development in other 
areas of disk-drive performance are 
now being applied to the develop- 
ment of products suitable for smaller 
systems. The tremendous growth of 
microcomputers has created a de- 



GrnaphJca 

The Paper Tiger 'puts mare bile into 

everything you da 



The Paper Tiger strikes again. With a DotPlot"" graphics 
option that lets you make the most of your Apple II, TRS 80* 
or other personal computer.. 

With DotPlot and available software drivers, 
you can print screen graphics, draw illustrations, 
write block letters, plot charts. And DotPlot 
includes an expanded, 2K-byte buffer. 

That's not all. Every Paper Tiger gives you 8 
software-selectable character sizes. 80 and 
132 column formats. Multi-part business forms 
handling. Forms control. Reliable stepper- 
motor paper drive. Adjustable width tractor feed. 
Continuous duty cycle operation. Plus lots more. 

t Apple II is a trademark of Apple Computer Inc. 

^TRS-80 is a trademark of Radio Shack, a division of Tandy Corp. 



The Paper Tiger costs only $995. The DotPlot option only 
$99 more. But don't let these low prices fool you. Because the 
Paper Tiger is rugged enough to stand up to the 
most demanding printer-plotter requirements. 

fFor the name of the Paper Tiger dealer nearest 
• you, call toll-free 1-800-343-6412 (except Massa- 
chusetts, Alaska, and Hawaii). 
Integral Data Systems, 14 Tech Circle, 
Natick, MA 01760. (617) 237-7610. 

Circle 38 on inquiry card. 




Integral Data Systems, Inc. 




mand for small, compact disk drives. 
The industry has responded and is be- 
ginning to produce them. A 
Winchester disk drive for your per- 
sonal computer is now, or soon will 
be, a possibility. However, it may 
still cost you five to ten times the 
price of your processor to get a com- 
plete small hard-disk subsystem with 
drive, controller, interface, power 
supply, and packaging. 




Photo 2: Close-up of a Winchester-type 
read/write head. (Photo courtesy of 
Kennedy Company.) 




Photo 3: The remarkable Shugart 
Technology Model ST506 hard-disk 
drive, offering 6 megabytes of mass 
storage in a 3.5-pound package that fits in 
the same space as a 5-inch floppy-disk 
drive. (Shugart Technology is a new com- 
pany located in Scotts Valley, California, 
and is not affiliated with either Shugart 
Associates or Xerox. Photo courtesy of 
Shugart Technology.) 



What Is Winchester Technology? 

Three disk technologies have 
evolved, all pioneered by IBM. Other 
manufacturers have refined the 
designs. These technologies are usual- 
ly referred to by the model numbers 
of the original IBM product employ- 
ing the technology: "2314" 
technology (in the 1960s), "3330" 
technology (late 1960s, early 1970s), 
and "Winchester" technology (1973). 

Disk storage, being a special type 
of add-on memory, can directly affect 
a computer system's performance, 
throughput, and reliability. Because 
of this crucial role, the principal 
design objectives for disks are large 
capacity, fast access time, absolute 
reliability, and low cost. 

Each of the three advances has 
brought a significant increase in 
storage density. One way to increase 
density is to reduce the flying height 
of the heads over the disk surface. 
Each reduction in height allows an in- 
crease in tpi (tracks per inch) and bpi 
(bits per inch) (see figure 1). Ad- 
vances in head design and positioning 
mechanisms have also contributed to 
increases in tpi and bpi. 

Head flying heights have evolved 
as shown in table 1. 

Just prior to 1973, disk-drive 
technology approached some limits. 
The flying height had been reduced to 
31 microinches. Without further 
reduction, significant improvement in 
data density was difficult. At lower 
flying heights, a single smoke parti- 
cle, whose diameter may be up to ten 
times the distance between the head 
and disk surface, can damage the disk 
and data. Therefore, cleaner condi- 
tions were required. Also, the disk 
platters and magnetic surfaces were 
inadequate for large increases in track 
and bit densities. 

The 3340 Winchester disk drive, in- 
troduced by IBM in 1973, was the 
first breakthrough. Storage 
Technology Corporation announced 
a similar disk drive around the same 
time: the STC 8800 superdisk. 

Winchester Characteristics 

Winchester disk drives have the 
following characteristics: 

• sealed disk, head, and position- 
ing assemblies 

• new trimaran head design — two 
outriggers supporting a narrower 
inner hull containing the 
read/write head (see photo 2) 



• thinner magnetic coating: 44 
microinches versus 185 micro- 
inches in the 2314 disk drive 

• lubricated disk surfaces 

• heads resting on disk surface 
when drive is stopped — they take 
off and fly low when motion 
starts (normal take-off and land- 
ing are done on an area reserved 
for that purpose) 

• light loading force (10 g) and 
lighter heads. 

These characteristics permit many 
performance improvements: very low 
flying heights (19 to 20 microinches), 
improved reliability, and a dramatic 
reduction in head crashes are possible 
because of the clean environment, 
new head and loading designs, and 
lubrication. Data densities are in- 
creased because of lower flying height 
and thinner platter coating. The 
higher densities improve throughput 
performance directly. More bits per 
inch allow more data to pass under 
the heads per unit time. More tracks 
per inch mean that track-to-track ac- 
cess times are shorter. The lighter 
heads and head mounts have less in- 
ertia and can be positioned faster. 
Throughput performance can be im- 
proved by increasing the rotational 
speed, up to a point — the aero- 
dynamic characteristics of the flying 
head put some constraints on the 
rotational speed. The reliability of the 
Winchester drives surpassed that of 
any moving-head disk drive that was 
previously available. 

Improvements and refinements 
have continued from many manufac- 
turers. The costs of many of the most 
expensive elements in a disk (the 
motor, head actuator, and control 
electronics) are relatively indepen- 
dent of the capacity of the disk plat- 
ters. It is, therefore, cost-effective to 
increase the density of the platters 
and the number of platters. The in- 
centive has been to add capacity by 
any conceivable means, and trends 
have been toward more platters per 
spindle and greater bpi and tpi den- 
sities (data density has gone from 
about 1000 bpi on early 2314s to over 
8600 bpi on some of the recent disks, 
and tpi density has gone from 200 tpi 
on 2314s to over 600 tpi on new pro- 
ducts). Cost effectiveness has also 
been enhanced by reducing the access 
time and increasing the data flow; the 
economic payoff is increased 
throughput and efficiency of the total 



60 August 1980 © BYTE Publications Inc 



Hard and 
Fast... 




...Bulk Storage from 
Industrial Micro Systems 



THE NEW MODEL 16 

The new Industrial Micro Systems Model 16 Hard Disk 
Subsystem is a "fixed-removable" high speed, bulk 
storage device providing from 32 megabytes (32 
million characters) to 96 megabytes of on-line storage 
for the Industrial Micro Systems 8000 or Series 5000 
microcomputer systems. The Model 16 includes a 
credenza enclosure that provides a quiet, strong and 
attractive package for office 
or industrial applications 
where large memory is 
required. The Model 16 also 
includes a fully buffered 
DMA S-100 bus controller for 
fast and easy interfacing. 

WINCHESTER 
TECHNOLOGY WITH 
BUILT-IN BACKUP 

The Model 16 includes a 16 
megabyte removable 

cartridge and a 16, 48, or 80 




megabyte fixed media that employs Winchester 3340 
technology. Files and programs may be copied 
between the fixed media and the removable cartridge 
for fast, easy backup and archival storage. 

FAST ACCESS 

The interface between the Model 16 hard disk and the 

Industrial Micro Systems 
computer is provided by the 
Hard Disk Controller. The 
Hard Disk Controller utilizes 
Direct Memory Access (DMA) 
for fast data transfer with 
minimum processor interven- 
tion. The maximum data 
transfer rate is 1.2 megabytes 
per second and the controller 
fully buffers the data, a 
sector at a time, to and from 
the disk Available in 220 V, 
50 HZ Versions 



Now you don't have to look hard for fast computing power. Contact your Industrial Micro Systems Dealer today. 

INDUSTRIAL MICRO SYSTEMS 

Marketing Manufacturing 

628 N. Eckhoff, Orange, CA 92668 2800 Lockheed Way, Carson City, NV 89701 
(714)978-6966 (702)883-7611 

Circle 39 on inquiry card. BYTE August 1980 61 



system. In applications where disk 
storage is a key element, the pro- 
cessor is often disk-I/O-bound. Pro- 
gram execution speed depends on 
disk speed. Every increase in 
throughput will improve the total 
performance. 

Other improvements in throughput 
performance in disk subsystems have 




Photo 4: BASF Systems' 6170 Series 
8-inch, fixed hard-disk drive, available in 
8- and 24-megabyte versions. (Photo 
courtesy of BASF.) 



come from RPS (rotational postion- 
ing sensing), which frees the disk con- 
troller and I/O (input/output) chan- 
nel for other work during seek time 
(head actuator movement) and dur- 
ing part of the rotational delay time. 
Improvements have also included 
new automatic error detection, cor- 
rection, and recovery capabilities 
built into disk controllers. 

Voice-coil actuators, described in 
the next section, are common on 
high-performance disk drives. There 
are both linear and rotary voice-coil 
positioners. Rotary voice coils 
typically take up less space, require 
less power, and generate less heat 
than linear voice coils. Stepper 
motors with band actuators are 
usually used in lower-performance, 
lower-cost disk drives. Many of the 
new small drives use brushless DC 
(direct current) motors with direct 
drive on the platters. Designed as part 
of the spindles, these motors are com- 
pact (about 1 inch high), maintain 
speed more accurately, use less 
power, and require simpler power 
supplies than AC (alternating cur- 
rent) motors with belt drives. In 
many drives, each recording surface 
is split into inner and outer bands 
with a head for each band, reducing 
the average access time by one-half, 




because twice the amount of data can 
be read or written without moving 
the heads. 

Comparing the New Hard Disks 
to Floppy-Disk Drives 

The current trends toward multi- 
terminal systems, real-time transac- 
tion oriented systems, small business 
systems, and more powerful personal 
computers for a great variety of ap- 
plications have created a demand for 
more on-line data storage. Floppy- 
disk drives and tape cassettes often do 
not have the required performance 
(access times, throughput, etc), 
reliability, or capacities. Thus, the 
need for secondary storage is being 
filled by new, inexpensive, high- 
performance, highly reliable small- 
disk drives with capacities, speeds, 
and reliability close to the very ex- 
pensive drives. These new drives are 
physically much smaller and more 
reliable than 14-inch cartridge or 
disk-pack drives. They are aimed in- 
itially at a gap between floppy drives 
and 14-inch drives (eg: Winchester, 
5440 cartridges and 3330 type packs). 
They are designed for use on small 
business systems, distributed- 
processing systems, word-processing 
systems, and advanced personal com- 
puter systems. 

The new drives offer a lower cost 
per unit than 14-inch drives, and 
lower cost per byte than floppy-disk 
drives. They provide the advantages 
in capacity and performance of hard 
disks in a package the same size as an 




Photo 5: Priam 14-inch (at left) and 8-inch Winchester hard-disk drives. (Photo 
courtesy of Priam.) 



Photo 6: Kennedy Series 7000 8-inch 
hard-disk drive. (Photo courtesy of 
Kennedy Company.) 



62 August 1980 © BYTE Publications Inc 












Multi-User 



UniFLEX is the first full capability multi-user 
operating system available for microprocessors. 
Designed for the 6809 and 68000, it offers its 
users a very friendly computing environment. 
After a user 'logs-in' with his user name and 
password, any of the system programs may be 
run at will. One user may run the text editor 
while another runs BASIC and still another runs 
the C compiler. Each user operates in his own 
system environment, unaware of other user 
activity. The total number of users is only 
restricted by the resources and efficiency of the 
hardware in use. 



Supp 



The design of UniFLEX, with its hierarchical file 
system and device independent I/O, allows the 
creation of a variety of complex support 
programs. There is currently a wide variety of 
software available and under development. 
Included in this list is a Text Processing System 
for word processing functions, BASIC interpreter 
and precompiler for general programming and 
educational use, native C and Pascal 
compilers for more advanced programming, 
sort/merqe for business applications, and a 
variety ofdebug packages. The standard 
system includes a text editor, assembler, and 
about forty utility programs. UniFLEX for 6809 is 
sold with a single CPU license and one years 
maintenance for $450.00. Additional yearly 
maintenance is available for $100.00. OEM 
licenses are also available. 



FLEX 



Multi-Tasking 



UniFLEX is a true multi-tasking operating system. 
Not only may several users run different 
programs, but one user may run several 
programs at a time. For example, a 
compilation of one file could be initiated while 
simultaneously makinq changes to another file 
using the text editor. New tasks are generated 
in the system by the 'fork' operation. Tasks may 
be run in the background or 'locked' in main 
memory to assist critical response times. Inter- 
task communication is also supported through 
the 'pipe' mechanism. 



UniFLEX is offered for the advanced 
microprocessor systems. FLEX, the industry 
standard for 6800 and 6809 systems, is offered 
for smaller, single user systems. A full line of FLEX 
support software and OEM licenses are also 
available. 



Box 2570, West Lafayette, IN 47906 
(317) 463-2502 Telex 276143 

'"UniFLEX and FLEX are trademarks of Technical 
Systems Consultants, Inc. 

Circle 40 on inquiry card. 



Circle 41 on inquiry card. 



The days of complicated, unreliable, 
dynamic RAM are gone: 




the ultrabyte memory board 



Q1QQ QR (complete kit \ 

O l?J?J •*** \withl6K memory J 

Nelronics consistently offers innovative products at un- 
beatable prices. And here we go again — with JAWS, 
the ultrabyte 64K S100 memory board. 
ONE CHIP DOES IT ALL 
JAWS solves the problems of dynamic RAM with a 
state-of-the-art chip from Intel that does it all. Intel's 
single chip 64K dynamic RAM controller eliminates 
high-current logic parts . . . delay lines . . . massive 
heat sinks . . . unreliable trick circuits. 
REMARKABLE FEATURES OF JAWS 
Look what JAWS offers you: Hidden refresh . . . fast 
performance ... low power consumption . . . latched 
data outputs ... 200 NS 41 16 RAMs . . . on-board 
crystal . . . 8K bank selectable . . . fully socketed . . . 
solder mask on both sides of board . . . designed for 
8080. 8085. and Z80 bus signals . . . works in Explorer, 
Sol, Horizon, as well as all other well-designed S100 
computers. 

I GIVE YOUR COMPUTER A BIB BYTE OF MEMORY | 
POMRW1TH JAWS— SAVE UPT0»9O ON 
INTRODUCTORY LIMITED-OFFER SPECIAL PRICES! | 

UNDECIOED? THY A WIRED IBK JAWS IN YOUR COMPUTER ON OUR 
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COMTHKHTAl U.S A CREDIT CMO BUYERS OUTSIDE CONNECTICUT CALL 



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f^vNETRONICS; 



CALL TOLL FREE 800-243-7428 

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IDEVELOPMENTLTDJ 

333 Litchfield Road, New Milford.CT 06776 
Please send the items checked below: 
n JAWS 16K RAM kit, No. 6416, S199.95* 
D JAWS 16K RAM fully assembled, testad, burned in. 

No. 6416W, $229.95.* 
G JAWS 32K RAM kit, No. 6432, (reg. price $329.95). 

SPECIAL PRICE *299 95 * 
G JAWS 32K RAM fully assembled, tested, burned in. 

No. 6432W. (reg. price $369.95), SPECIAL PRICE 

♦339.98.* 
G JAWS 48K RAM kit. No. 6448. (reg. price $459.95), 

SPECIAL PRICE (399.95.* 
G JAWS 48K fully assembled, tattad, burned in. No. 

6448W. (reg. price $509.95). SPECIAL PRICE 

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□ JAWS 64K RAM kit, No. 6464, (reg. price $589.95). 

SPECIAL PRICE M99.95* 
: i JAWS 64K RAM fully auambled. taitad, burned in, 

No. 6464W. (reg. price S649.95), SPECIAL PRICE 

•559.95* 
. i Expansion kit, JAWS 16K RAM modula, lo expand 

any of the above in 16K blocks up lo 64K, No. 16EXP. 

S129.95.* 

'All prices plus $2 postage and handling. Connecticut 

residents add sales tax. 
Total enclosed: $ 



G Personal Check G Money order or Cashiers Check 

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S-inch or even a 5-inch floppy-disk 
drive — many will actually fit the 
panel openings for floppy-disk 
drives. Reliability will be better than 
with floppy and cartridge drives, and 
power consumption will be signifi- 
cantly lower than that of the 14-inch 
drives. 

Systems based on 16-bit processors 
or microcomputers often require 
much more and much faster secon- 
dary storage than floppy disks can 
provide. The more sophisticated 
multiprogramming and file- 
management software currently being 
added to small computer systems re- 
quires so much continuous use of 
mass storage that the high perfor- 



TPI — 




BPI 



Figure 1: Detail of hard-disk surface, il- 
lustrating the ideas of tpi and bpi. 



mance and durability of hard disks 
may soon be a necessity. 

The new 8-inch and 5-inch disk 
drives offer several advantages over 
both floppy and 14-inch hard drives: 

• They have five to sixty times the 
storage capacity of a floppy-disk 
drive in the same space. 

• They access data four times faster 
than the floppy-disk drive. 

• They weigh less, take up less 
space, and use less power than 
14-inch drives. 

• They are only three to five times 
more expensive than floppy-disk 
drives, with cost reductions like- 

ly. 

The availability of low-cost-per- 
function hard disks has long been 
awaited by the small system 
marketplace. The wait is all but over. 
This summer a score of products are 
scheduled to be available, at least in 
sample or evaluation quantities. 

Though many of the new small 
disk products are advertised as fitting 
the same 4.6 by 8.5-inch opening as 
the standard floppy-disk drive 
(Shugart Technology's 5-inch Micro 
Winchester fits a 5-inch floppy-drive 
opening, see photo 3), a floppy-disk 
drive cannot literally be pulled out 
and replaced by the hard drive. To 
begin with, the packages contain dif- 
ferent electronics. Most of the drives 



Head flying height 

(in microinches) 



2314 

100 to 120 



3330 

31 to 45 



Winchester 

19 to 20 



Table 1: Evolution of head flying heights in hard-disk drives. 





Floppy-Disk Drives 


Hard-Disk Drives, 

Cartridges and Disk 

Packs 


Standard platter 
diameters 


8-inch 
5-inch 


14-inch, 8-inch, 
and 5-inch 


Capacity 


100 K bytes to 1 megabyte 


2 megabytes to 300 + 
megabytes 


Average Access Time 


0.1 to 1 second 


25 to 70 ms 


Rotational Speed 


300 rpm 


2400 to 4700 rpm 


Reliability and Useful 
Life Relative to Floppy- 
Disk Drives 


1 


2 + 


Table 2: Technical comparisons between floppy-dbk drives and hard-disk drives, 
cartridges, and disk packs. 



64 August 1980 © BYTE Publications Inc 



Look what's happened to 



HIPL0T 



TM 



DMP-4 
$1,385- 



DMP-3 
$1,250' 







DMP-6 
$1,850' 



DMP-7 
1,985- 






It's grown into a complete 
family of quality low cost digital plotters 



In just two short years, The 
HIPL0T has become the most 
popular digital plotter among 
small systems users. With a 
record like that, what can we do 
for an encore? WE'VE IN- 
TRODUCED A COMPLETE LINE 
OF HIPL0TS...with a model 
suited for just about every plot- 
ting application. 

The HIPL0T DMP Series is a 
new family of digital plotters 
with both "standard" and "in- 
telligent" models available with 
surface areas of 8V2" x 11" (DIN 
A4) and 11" x 17" (DIN A3). For 
the user needing a basic reliable 
plotter, we have the "old stan- 
dard" DMP-2 (8V2" x 11") and the 
"new standard" DMP-5 (11" x 
17"). For those needing a lit- 
tle more capability, there are 
the DMP-3 (8 1 / 2 " x 11") and 
the DMP-6 (11" x 17")-both 



TM HIPLOT and DM/PL are Trademarks 
of Houston Instrument 

Circle number 42 for literature 

Circle number 216 to have a representative call 



Yes, they are UL listed!** 

microprocessor controlled and 
providing easy remote position- 
ing of the X and Y axes (perfect 
for the OEM). For those who 
want this intelligence plus the 
convenience of front panel elec- 
tronic controls, we've provided 
the DMP-4 (8 1 / 2 " x 11") and the 
DMP-7 (11" x 17"). 

The "standard" plotters come 
complete with an RS-232-C and 
a parallel interface. The "intel- 
ligent" DMP plotters accept data 
from either an RS-232-C or Centronics 
data source. For the "standard" plot- 
ters, software is available from 
our ever expanding "Micrographic 
Users Group." The "intelligent" 
HIPLOTs use our exclusive 
DM/PL™ language which min- 
inimizes plot software to a 
fraction of that normally as- 

houston instrument 

GRAPHICS DIVISION OF 

BAUSCH&LOMB 



sociated wth digital plotting. 

With the new DMP Series, 
high quality digital plotting can 
now be a part of your system. It 
just doesn't make sense to be 
without this valuable tool when 
there is a DMP plotter with the 
plot size, speed and capabilities 
that are exactly tailored to your 
specific needs. ..and your 
budget. 

Prices for the DMP series 
range from $1,085* to $1,985". 
For complete information and 
descriptive literature, contact 
Houston Instrument, One 
Houston Square, Austin, Texas 
78753. (512) 837-2820. In Europe 
contact Houston Instrument, 
Rochesterlaan 6 8240 Gistel, 
Belgium 059/277445. For rush 
literature requests and sales of- 
fice information, persons 
outside Texas call toll free 
1-800-531-5205. 

'U.S. suggested retail prices only. 
■-DMP2, 3 and 4 UL listed 
DMP 5, 6 and 7 UL listing pending 





Memorex Corporation 
Santa Clara CA 


New World Computer 

Co Inc 

Costa Mesa CA 


Shugart Associates 
Sunnyvale CA 


Shugart Technology 
Scotts Valley CA 


Model 


101 


211 


SA1002/SA1004 


ST506 


Unformatted Capacity 
(millions of bytes) 


11.7 


2.1 


5.33/10.67 


6.38 


Platter Size 
millimeters and (inches) 


200 (7.87) 


8 inch 


200 (7.87) 


130(5.12) 


Number of Platters 


2 


1 


1 or 2 


2 


Average Access Time 


70 ms 


18.825 ms 


70 ms 


170 ms 


Maximum Data Transfer Rate — 
(K bytes per second) 


756 


543 


625 


Average Latency 


10.1 ms 


8.825 ms 


9.6 ms 


8.3 ms 


Rotational Speed 


2964 rpm 


3600 rpm 


3125 rpm 


3600 rpm 


Motor Type 


DC 


— 


AC 


brushless DC 


Spindle Drive 


direct drive 


— 


belt drive 


direct drive 


Actuator Type 


high speed band 


simplified band 


band 


band 


Positioning Mechanism 


open loop stepper motor 


stepper motor 


stepper motor 


open loop stepper motor 


Density bpi 


6100 


8000 


6270 


7690 


Density tpi 


195 


100 


172 


254 


Physical Size 
(inches) 


4.38 by 8.55 by 14 


2 by 9.5 by 9.5 


4.62 by 8.55 by 14.25 


3.25 by 5.75 by 8 


Weight (pounds) 


10 


8 


17 


3.5 


Single Quantity Price 


— 


$4,500 


$1,600/$1,980 


$1,500 


OEM Discount Price 


$1,200' 


$1,250 


$1,140/51,400 


$925 


Cost Per Thousand Bytes 
(OEM Discount) 


$.103 


$.595 


$.214/$. 131 


$.145 


Comments 


Includes a data 
separator 


20 heads, 8 tracks per 

head. Low-end only in 

capacity, not in 

performance. 




First micro Winchester 

Drive. Fits 5-inch floppy 

space 


Table 3: 


Specifications and characteristics of low-end, 5-inch 


and 8-inch hard-disk d 


■ives. 



have the basic drive electronics, 
signal amplifiers, read/write elec- 
tronics, and motor and servo control 
circuitry integrated into the package. 
Some have room to add optional, 
separately priced controllers to do 
error-checking and correction, data 
formatting, and interfacing to the 
computers. 

Stepper-motor actuators are a 
technique borrowed from floppy 
drives for use in hard-disk drives. 
This idea allowed lower prices for 
Winchester-technology units such as 
the 14-inch Shugart SA4000 and 
Century Data Systems Marksman, 
but at a cost of greater access time 
and reduced storage capacities when 
compared with voice-coil actuator- 
based units. 

A voice-coil actuator is a cylin- 
drical, permanent magnet with a hole 



machined from pole to pole. A coil 
rides on bearings within the magnet 
and moves back and forth. The 
read/write positioning mechanism 
with electromagnetic heads is 
attached to the coil. A voice-coil ac- 
tuator is positioned by servo-control 
with servo tracks written on one plat- 
ter's surface at the factory. 

Voice-coil actuators allow in- 
creases in data-storage capacity 
because their accuracy in small 
movements allows high tpi densities. 
Since the distance between tracks is 
smaller, access time is reduced. Also, 
voice-coil actuators do not impose 
the additional penalty of settling 
time. 

One disadvantage of a voice-coil 
actuator is the magnetic field pro- 
duced by the coil: the coil's magnetic 
field must not get too close to the disk 



platters or it could erase them. Effi- 
cient design can keep the magnetic 
field intensity at a safe level near the 
recording surfaces. Table 2 gives a 
partial technical comparison between 
floppy-disk drives and hard disks. 

Future Technological Progress 

Some of the more recent develop- 
ments in heads (such as thin film 
heads) and disks (thin-film-plated 
disks) mean that data densities will 
probably advance from the presently 
attainable 8 to 10 megabytes per 
8-inch surface to 50 or more mega- 
bytes per surface as track densities 
of 1000 tpi and bit densities of 10,000 
bpi are achieved. A small, relatively 
inexpensive disk drive could then 
store 100 megabytes or more of data 
with an additional 100 megabytes 
added for nominal cost. Thin-film 



66 August 1980 © BYTE Publications Inc 



AIM 65. The professional's 
microcomputer. 




Printer, display, full keyboard. Under $500.00. 




For professional learning, 
designing and work, Rockwell's 
AIM 65 microcomputer gives you 
an easy, inexpensive head start. 
That's Rockwell Micropower! 



• 20-column printer and display 

• Dual cassette, TTY and 
general purpose I/Os 

• R6502 NMOS microprocessor 

• System expansion bus 

• Read/write RAM memory 

• Prom/ROM expansion sockets 

• Self-prompt interactive 
monitor firmware 

• Big terminal-style keyboard 
For more on AIM 65 and how 



€> 



you can develop programs in 
assembly language or BASIC, 
write Rockwell International, 
Microsystems, RC 55, 
P.O. Box 3669, Anaheim, 
CA 92803 or contact your 
local Rockwell distributor. 
For application information 
call (714) 632-3729. For location 
of nearest dealer call 
800-854-8099, in California 
800-422-4230. 



Rockwell International 

...where science gets down to business 



Circle 43 on inquiry card. 



BYTE August 1980 67 



technology may be the next break- 
through in mass-storage techniques. 

Secondary storage and storage 
backup are currently being supplied 
by a wide variety of devices, 
including 

cassette tapes 

8-inch floppy-disk drives 

5-inch floppy-disk drives 

reel-to-reel magnetic tapes 

cartridge magnetic tapes 

cartridge-disk drives 

disk-pack drives 

fixed storage Winchester drives 

combinations: fixed Winchester- 
disk /cartridge-disk drive or 
fixed Winchester/magnetic- 
tape cartridge 

streaming-tape drives 

bubble memories 

nonvolatile semiconductor 
programmable memory 

videocassette recorders 

video disks 

The last three or four types are 
more for the future than now. Bubble 
memories and nonvolatile integrated 
circuits will have the great advantage 
of no moving parts and the potential 
convenience of plug-in modules; but 



they are still quite expensive. At least 
one interface and controller for 
American and European standard 
VCRs (videocassette recorders) is 
available to provide removable back- 
up for high-capacity disks on small 
systems (the Corvus Mirror, manu- 
factured by Corvus Systems Inc, San 
Jose, California). It stores up to 100 
megabytes on one videocassette and 
has a transfer rate of 15 K bytes/se- 
cond. Video disks have the potential 
to offer extremely high data-storage 
capacity and fast access rates (up to 
1250 megabytes per 12-inch disk, 
equal to approximately four times the 
contents of the Encyclopaedia Britan- 
nica). 

Small vs Large Hard-Disk Drives 

Hard-disk drives for small systems 
fall roughly into two size categories: 
up to 12 megabytes and over 12 
megabytes; and two performance 
categories: slow, with stepping-motor 
positioning, and fast, with voice-coil 
positioning. Those with stepping- 
motor positioning have average ac- 
cess times of 70 ms and capacities of 
under 12 megabytes. The drives with 
fast voice-coil positioning have 



average access times ranging from 
25 ms to 50 ms, with models that fall 
into both size categories. The less ex- 
pensive units are aimed at replacing 
floppy-disk drives directly. Examples 
of this type of product are the 
Memorex 101, the Shugart Associates 
SA-1000 series, and the Shugart 
Technology ST 506. The high end is 
led by IBM with the Piccolo drive, 
which is integrated into the System 
34, and is an add-on peripheral for 
the Series 1. It features a rotary voice 
coil, 17 ms average access time, and 
up to 64.5 megabytes of storage 
capacity. Other contenders in this 
category offer high performance in a 
wide range of sizes (eg: the BASF 
Systems 6170 Series, IMI (Interna- 
tional Memories, Inc) 7700 Series, 
Kennedy Company 7000 Series, 
Microcomputer Systems MSC-8000, 
Micropolis Corporation Micro Disk 
1200 Series, Pertec Computer Cor- 
poration D-8000, and Priam Diskos 
2050/3450). 

The disk capacity and the perfor- 
mance you need depend on your par- 
ticular application, which in turn has 
a significant impact on the cost of a 
system. Small-system applications, as 



PRINTERS & CRT'S From Orange micro 




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CPS • Fast form feed • User programmable character 
set • 64, 72, 80, 96, 120, 132 Columns/ line • Expanded 
characters • 9.5" wide paper • Automatic skip-over- 
perforation • Horizontal & Vertical tabs • Programmable 
vertical line spacing • Intel 8085 Microprocessor — over 
40 software commands • Self test • 15 Baud rates to 
9600 Baud • Optional foreign character sets 

Interfaces to TRS-80, Apple, Atari, PET, Northstar, and most 
other computers. 

Circle 44 on inquiry card. 




TELEVIDEO CRT'SI 

PRICES SLASHED! 



91 2C 
920C 



$CALL 
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AXIOM 

IMP-1 629 

IMP-2 715 

Other models $ Call 

CENTRONICS 

779 w/tractors 1059 

730 $ Call 

737 $Call 

COMPRINT 

912 Parallel 499 

912 Serial 535 



PRINTERS 

OKIDATA 



Microline80 659 

w/tractors 779 

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toll free (800) 854-8275 

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Phone orders WELCOME. Same day 
shipment for VISA, MASTER 
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ping and handling. California resi- 
dents add 6%. Manufacturer's 
warranty included. Prices subject to 
revision. 



J 



Orange 
micro 

P.O. Box 2076 
Yorba Linda, CA 92686 



What's the difference 
between b&s ic and rascal? 

COMPARE THESE APPROACHES TO DRAWING A CIRCLE 

m Bfcsic 



"This is easy . 



loo Move* Rp 

1 10 for t*~o to 3<*> snrp zsr 

ISO NEXT T 



"Oops, didn't quite meet . . . 



. . . but that's easy to fix. 



100 HlOVE 1 R>0 




I 10 FOR T-0 TD 36c / STEl» 2ST 

130 N^XTT 



"Oft, now it closes . 
in fact, it overlaps. 



Programming by trial and error 




in Pascal 

"The simplest circle drawn with line 
segments is a regular polygon ..." 



procedure Circle (X, Y, Radius: real); 
const Sides = 16; Pi = 3.14159265; 
var N : integer; Theta : real; 
begin 

Move (X+Radius,Y); 
for N : = 1 to Sides do begin 
Theta : = 2 * Pi * (N/Sides); 
Draw (Radius * cos (Theta) + X, 
Radius * sin (Theta) + Y); 
end; 
end; 




Programming by design 



GET IT RIGHT THE FIRST TIME 



INTERNATIONAL 
DISTRIBUTORS 

Australia: Sydney 

Network Computer Services 

290-3677 

Canada: Vancouver 
Valley Software 
(604) 291-0651 

England: London 
Real Time Products 
01-588-0667 

Japan: Tokyo 
Rikei Corporation 
03-345-1411 



If you like the feel of precision tools, give us a call or return this coupon. 



Name 




ft 



Firm 



Software 



Address 



City _ 
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By 8 



Circle 45 on inquiry card. 



BYTE August 1980 69 



mentioned before, can be placed in 
two major classes: single-user, single 
task and multi-user, multi-task. 

• Single-user, single-task systems 
are usually stand-alone work- 
stations, intelligent terminals, or 
personal computers. Their chief 
use of magnetic storage, in 
general, is for program storage 
and data storage. The amount of 
storage required is often less than 
10 megabytes. Because the speed 
need only match one human 
operator's response time, there is 
no benefit to be derived from 
disks with extremely fast access 
times. An average access time of 
70 ms is usually sufficient in such 
applications. This class of ap- 
plication is cost-per-unit- 
oriented, since the storage device 
is dedicated to one user. It is 
price-oriented, and performance 
is not a vital factor. The low-end, 
small hard-disk drives fill this 
need splendidly. 

• Multi-user, multi-task systems re- 
quire that more than one, 
sometimes many, users have ac- 
cess to a common data base. 



They typically require from 30 to 
100 megabytes of magnetic 
storage, usually on one spindle. 
Some require less storage and 
some will require multiple 
spindles. The cost per byte of 
storage is a more important con- 
sideration than the cost per drive 
unit, because the basic device 
cost is spread over many users. 

Multi-user, multi-task systems re- 
quire an average access time of 50 ms 
or less because multiple users must 
contend for the common storage de- 
vice. The main purpose of these ap- 
plications is usually not to share the 
processing power, but rather to share 
the data. These systems are often 
"disk-bound" rather than "computer- 
bound." Disk performance becomes a 
critical factor in system performance. 
Even when the disk capacity required 
might be relatively small (8 to 10 
megabytes), the fast performance of 
the high end mini-disks will be re- 
quired. 

With their faster access times, 
higher capacities, greater reliability 
and OEM (original equipment manu- 
facturer) quantity prices ranging from 



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70 



August 1980 © BYTE Publications Inc 



Circle 46 on inquiry card. 



$1000 to $5000 (some may soon drop 
below $1000), both classes of the new 
hard-disk drives should be attractive 
to personal-computer systems 
builders who want additional 
capacity and performance, but not 
the traditional 14-inch disk size and 
price per unit. Some complete 
packages of drives, controllers, inter- 
faces, and power supplies are 
available for about $5000. Even 
though they cost five to ten times as 
much as the processor, these units are 
still cheaper per drive than 14-inch 
drives. They are also applicable 
where more capacity and perfor- 
mance than a floppy disk can supply 
are needed, but the space or the cost 
of a 14-inch disk drive is prohibitive. 
Tables 3, 4, and 5 list some of the cur- 
rent disk-drive products for small 
systems. The reliability and main- 
tainability of these products are 
essentially high and are consistent 
across the board. (See table 6.) 

Controllers and Interfaces 

One of the problems with the new 
8-inch hard-disk drives is the variety 
of interface systems to choose from. 
Such variety is inevitable at this stage 
because of the many personal com- 
puters already on the market, and the 
diversity of interface requirements. In 
the absence of a comprehensive inter- 
face standard, many of the drive sup- 
pliers have designed their own. A 
similar situation has developed in the 
audio industry. Consider the many 
types of noncompatible audio record- 
ing standards including: the LP (long- 
playing) record, 45 rpm records, open 
reel tapes, cassettes, and eight-track 
cartridges. This kind of variety at the 
outset of new products is not neces- 
sarily bad — there is much freedom for 
innovation. 

In August of 1979 an ANSI (Amer- 
ican National Standards Institute) 
Subcommittee (number X3T9.3) 
began to standardize an interface for 
8-inch hard disks. If a standard inter- 
face is widely accepted by the in- 
dustry, users may soon be able to in- 
terface drives from several vendors. 

Types of Interfaces 

There are two main categories of 
disk-drive interfaces, device level and 
host level. The main characteristics 
for the device level are-. 

• serial data transfer 

• formatting/de-formatting exter- 
nal to drive 

Text continued on page 138 
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Programming Cuicfcies 



Self-Reproducing 
Programs 



John Burger, David Brill, Filip Machi, 

System Development Corporation, 2500 Colorado Ave, 

Santa Monica CA 90406 

Listing 1 is a C program that duplicates itself. When the 
program is run it produces (on the standard output) a file 
containing an exact copy of its own source code. This 
program runs under the UNIX operating system and uses 
the American Standard Code for Information Inter- 
change (ASCII) character set. If this program is compiled 
on a system using a different character set, the octal 
values of "q" and "n" must be changed to the numbers 
representing that system's codes for the quote and new- 
line (or linefeed) characters, respectively. 

Why We Wrote a Self-Reproducing Program 

A while back, Pascal News contained a listing of a 
Pascal program called PRINTME that performs this feat. 
(See reference.) The Pascal listing took 46 lines of code. 

We are currently writing a large system in the C lan- 
guage. We considered the Pascal program to be an 
unstated challenge, and in response we wrote a C version 
of the PRINTME program that works pretty much the 
same way as the Pascal version. This version is shown in 
listing 2. 

This version is more elegant than the Pascal version 
and is 12 lines shorter. It takes a total of decimal 1313 
bytes to store the source code. Then, one of us who once 
had done a lot of LISP programming wrote a LISP func- 
tion that evaluates to itself. This function takes exactly 
279 bytes of memory in which to store the print image of 
the code. The LISP function is shown in listing 3. 

A week or so after the LISP function had been written, 
we were all discussing the similarities of LISP and C. 
From this discussion, we developed the C program of 
listing 1. It works like the LISP function and takes 126 
bytes in the source code file. 

For purists, though, a still shorter C version can be 
written. The C compiler, like a LISP compiler, sees all 
programs as a stream of bytes, and linefeed characters are 
parsed as spaces. Thus a C program could be written all 
on one line. The program in listing 4 is written on a single 
line in order to remove the necessity of printing linefeeds 
in the internal print. 

Note that the octal ASCII values for the quote and line- 
feed characters have been replaced by decimal values 
(gaining one byte per number) and that all linefeeds ex- 
cept the last have been removed. Our C compiler seems 
to require at least one linefeed at the end of the file. The 
source code for this program is only 101 bytes longlH 



The 



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Jerry Pournelle 
On Computing, Summer 1980 

4 i The basic functions of the Magic Wand editor are as easy to learn 
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On Computing, Summer 1980 

4 4 Of all the word processors I have used (and that includes a dozen 
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Microcomputing, June 1980 

4 4 The Magic Wand is one of the most flexible word processing 
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Creative Computing, August 1980 

Available for both the CP/M" and OASIS operating systems 

srcuxU business applications, lac. 

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Circle 49 on inquiry card. 



Electric Pencil is a trademark of Michael Shrayer Software, Inc 
WordStar is a trademark of Micro Pro International, fnc. 
C1VM is a registered trademark of Digital Research Corp 

BYTE August 1980 73 



Circle 50 on inquiry card. 



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Listing 1: Four-line C program which duplicates itself without any user input. If a non- 
ASCII character set is used on your system, the values of "q" and "n" must be changed 
to the values representing that system's quote and newline (linefeed) characters. 

main ( ) 1 

char q=042,n=P12, 

*a="raain() I %cchar q=042,n=012,%c*a=%c%s%c; %cpr intf (a,n,n,q,a,q,n,n) ; } %c" ; 

pr intf (a,n,n,q,a,q,n,n) ; ) 



Listing 2: Original self-duplicating C program. 

char *text 11=1 

"char *text | | = ( " , 

"0 );", 

"main ( ) { " , 

" char newline = 012, quote = 042, escape « 0134, *p, **pp; 

" printf (\"%s%c\", *text, newline);", 

" for (pp = text; *pp; pp++) {", 

" printf (\" %c\" , quote);", 

for (p = *pp; *p; p + + ) 1" , 
" if (*p == quote) " , 

" putchar (escape);", 

" putchar (*p) ; " , 

" printf (\"%c,%c\", quote, newline);", 

" for (pp = text + 1; *pp; pp++) " , 

" printf (\"%s%c\", *PP< newline);". 



); 
main ( ) i 



char newline = 012, quote = 042, escape = 0134, *p, **pp; 
printf ("%s%c", "text, newline); 

for (pp = text; *pp; pp++) ( 

pr intf (" %c" , quote) ; 
for (p = *pp; *p; P++) ( 
if (*p == quote) 

putchar (escape) ; 
putchar (*p) ; 

} 

printf ("%c,%c", quote, newline); 

1 

for (pp = text + 1; *pp; PP++) 

printf ("*s%c", *pp, newline); 



Listing 3: Self-duplicating LISP function which inspired the C program in listing 1. 

(PRTNTME (LAMBDA NIL (PROG (A B) 

(SETQ A (QUOTE (PRINTME (LAMBDA NIL (PROG (A B) 

(SETQ A (QUOTE FOO) ) 

(SETQ B (COPY A) ) 

(RPLACA (CDADDR (CADDAR (CDDADR B) ) ) A) 

(RETURN B) ) ) ) ) ) 
(SETQ B (COPY A) ) 

(RPLACA (CDADDR (CADDAR (CDDADR B))) A) 
(RETURN B) ) ) ) 



Listing 4: Final one-line, self-duplicating C program. This program is written on a single 
line to remove the necessity for code to generate linefeeds. However, the program is too 
long to display here without breaking the line. The program shown is to be written and 
compiled as a single line of source code. 

main()(char q=34 ,n=10 , *a="main ( ) {char q=34,n=10, 
*a=%c%s%c;printf(a,q,a,q,n) ; )%c";printf(a,q,a,q,n) ;) 



Reference 

Pascal News, Pascal Users' Group, number 12, June 1978. (Pascal Users' Group, c/o Andy 
Mickel, University Computer Center: 227 EX, 208 SE Union St, University of Minnesota, 
Minneapolis MN 55455.) 



74 August 1980 © BYTE Publications Inc 



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Circle 51 on inquiry card. 



BYTE Augusl 1980 75 



The Evolution of FORTH, 
an Unusual Language 



Charles H Moore 

FORTH Inc 

2309 Pacific Coast Hwy 

Hermosa Beach CA 90254 



Introduction 

When I invented FORTH about 10 
years ago, my goal was simply to 
make myself a more productive pro- 
grammer. When I first worked with 
computers at MIT and Stanford in the 
early 1960s, I figured that in 40 years 
a very good programmer could write 
forty programs. And I wanted to 
write more programs than that. There 
were things out in the world to be 
done, and I wanted a tool to help me 
do them. As I worked on programs 
that ranged from satellite orbits to 
chromatography to business systems, 
I developed FORTH in line with my 
overall goal. For several years now, I 
have been able to work at ten times 
my original rate. 

As I began thinking of rather 
drastic improvements to programs, I 
think I was arrogant. I wanted to do 
things my way. I was not convinced 
that I should not be permitted to, and 
I was a bit hard to get along with. The 
arrogance was necessary because I 
felt insecure. I was promoting ideas 
that everyone said were wrong and 
that I thought were right. But, if I 
were right, that meant that all the 



About the Author 

Cliarles H Moore is Chairman of the Board of 
FORTH Inc, a firm created in 1973 to provide 
application programming services and pack- 
aged FORTH systems. This article is adapted 
from a speech delivered at the FORTH Con- 
vention held in San Francisco in October 1979. 



other people would have been wrong, 
and there were many more of them 
than me. And it took a lot of 
arrogance to persist in the face of 
massive disinterest. 

FORTH is a polarizing concept. 
There are people who love it and peo- 
ple who hate it. It's just like religion 
and politics. If you want to start an 
argument, say, "Boy, FORTH's really 
a great language." 

This is partly because FORTH is an 
amplifier. A good programmer can 
do a fantastic job with FORTH; a bad 
programmer can do a disastrous job. 
I have seen very bad FORTH code 
and have been unable to explain to 
the author exactly why it was bad. 
There are some visible characteristics 
of good FORTH, such as very short 
definitions (many of ' them). Bad 
FORTH often takes the form of one 
definition per block — big, long, and 
dense. It is quite apparent, but dif- 
ficult to explain, why or how a 
FORTH program is bad. 

BASIC and FORTRAN are less sen- 
sitive to the quality of the program- 
mer. I was a good FORTRAN pro- 
grammer; I thought that I was doing 
the best job possible with FORTRAN, 
but it was not much better than what 
everybody else was doing. In this 
sense, FORTH is an elitist language. 

On the other hand, I think that 
FORTH is a language that a grade 
school child can learn to use quite 
effectively, if it is presented in bite- 



size pieces with the proper motiva- 
tion. 

FORTH is the first language that 
has come up from the grass roots. It is 
the first language that has been honed 
against the rock of experience before 
being standardized. I hesitate to say it 
is perfect; I will say that if you take 
anything away from FORTH, it is not 
FORTH any longer — the basic com- 
ponents are all essential to the viabil- 
ity of the language. 

History 

What might be called the 
prehistory of the FORTH language 
goes back much further than 10 
years. The first element of FORTH to 
exist was the text interpreter, shown 
in listing 1. This early version, pro- 
grammed in ALGOL at the Stanford 
Linear Accelerator Center in the early 
1960s, was part of a program called 
TRANSPORT, which designed 
electron-beam transport systems. 
Besides the text interpreter, this print- 
out also shows an early version of the 
dictionary. The influence of LISP is 
evident in the indivisible entity 
(which in FORTH is called a word) 
named ATOM. As the interpreter 
reads a word from a punched card, it 
executes the associated routine, as for 
DRIFT in this example. The style 
resembles that of modern FORTH: 
there is no limit on the length of a 
word, as you can see by the length of 
the word SOLENOID, but only the 



76 August 1980 © BYTE Publications Inc 



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first characters are significant and 
words are separated by spaces. 

Other very early concepts have 
either changed in form or have 
evolved dramatically. In listing 2, the 
word that has become { : } (colon) in 
modern FORTH is called DEFINE , 
while END has become { ; } 



(semicolon). This listing also shows 
stack operators being defined. As an 
example of a concept that has 
evolved, consider the dictionary 
being sealed by the word SEAL and 
broken by the word BREAK . Such 
sealing and breaking has since been 
replaced by the idea of vocabularies. 



Listing 1: An early version of the FORTH text interpreter (written in ALGOL). 

IF ATOM = "DRIFT" THEN DRIFT 
ELSE IF ATOM = "QUAD" THEN QUAD 
ELSE IF ATOM = "BEND" THEN BEND 
ELSE IF ATOM = "FACE" THEN FACE(-I) 
ELSE IF ATOM = "ROTATE" THEN ROTATE 
ELSE IF ATOM = "SOLENO" THEN SOLENOID 
ELSE IF ATOM = "SEX" THEN SEX 
ELSE IF ATOM = "ACC" THEN ACC 

ELSE IF ATOM = "MATRIX" THEN BEGIN IF NOT FITTING THEN BEGIN 
REAL A; 

WRITE1(3,0,0,CORE[S]); LINE( -(8 + 42 x (ORDER - 1))); 
FOR J-l STEP 1 UNTIL 6 DO BEGIN 

FOR K-l STEP 1 UNTIL 6 DO WRITE1(2,8,R1[J,K] xUNIT[K]/UNIT[I],2); 

LINE(O) END; 
IF ORDER = 2 THEN FOR C-l STEP 1 UNTIL 6 DO BEGIN 



Listing 2: An early version of the FORTH words { : } (called DEFINE here) and { ; } 
(called END here). 

"- "OPEN DEFINE MINUS + END 

SEAL "< "OPEN DEFINE - < END BREAK 

"NOT "OPEN DEFINE MINUS 1 + END 

"> "OPEN DEFINE •< END 

"AND "OPEN DEFINE x END 

"OR "OPEN DEFINE NOT .NOT AND NOT END 

"T 1 1 "REAL DECLARE 
"= "OPEN DEFINE T- ; DUP T< • T> OR NOT END 
"* "OPEN DEFINE = NOT END 
"< "OPEN DEFINE > NOT END 
"> "OPEN DEFINE < NOT END 
"DUMP "OPEN DEFINE NAME 10 "ALPHA WRITE; 3 10 "REAL WRITE LINE END 



Listing 3: Another prototype of the FORTH text editor, again in ALGOL. In this listing, 
the word ATOM (the predecessor of the basic unit in FORTH, the xoord) has been 
replaced by the word W . 

120 CYCLE; FILL OUTPUT WITH BUFFER[1],BUFFER[2]; 

1 WHILE WORD NEQ "END " DO 

2 IF W = GM1 THEN REPLYCOK ") 

3 ELSE IF NUMERIC THEN L: =MIN(W - l,$OF) 

4 ELSE IF W = "+ " THEN L: =MIN(L + WORD, EOF) 

5 ELSE IF W = "- " THEN L: =MAX(L -WORD.0) 

6 ELSE IF W = "T " THEN BEGIN 

7 IF WORD = GMl THEN W: = l; W: =MIN(L + W - 1 ,EOF); 

8 FOR L: = L STEP 1 UNTIL W DO BEGIN 

9 POSITION; TYPE END; L:=L-1 END 
130 ELSE IF W="R " THEN BEGIN 

1 POSITION; REPLACE END 

2 ELSE IF W = "A " THEN BEGIN 

3 L; = EOF: = EOF+l; REPLACE END 

4 ELSE IF W = "I " OR W = "D " THEN BEGIN 

5 IF NOT RECOPY THEN BEGIN 

6 RECOPY: =TRUE; REWIND(CARD) END; 

7 POSITION; IF W = "I " THEN BEGIN 

8 PLACE; REPLACE END 

9 ELSE BEGIN EMPTY: = TRUE; IF WORD NEQ GM1 THEN BEGIN 
140 L:=MIN(L + W-l,EOF); SPACE(CARD,L - L0+ 1); L0: = L + 1 

1 END END END 



Listing 3 shows another prototype 
in ALGOL, this time of a FORTH text 
editor. Here ATOM has become W 
and I am looking up plus, minus, and 
the commands T, R, A, and I, to edit 
a deck program. 

Another method of implementing a 
dictionary is shown in listing 4. I am 
looking up the words in a conditional 
statement and setting NEXT, the key 
routine of modern FORTH's address 
interpreter, to the index. 

Listing 5 shows an early implemen- 
tation of a stack. Since it is written in 
BALGOL, which allows assignment 
statements inside other statements, I 
could replace STACK[J] with [J + l] 
in order to push items onto the stack. 
I did this so that I could manipulate 
parameters that were interpreted 
from the card deck as arguments to 
the routines. When I wanted, for 
instance, to convert angular measure 
from one unit to another, this added 
the ability to use arithmetic 
operators. 

From Stanford I moved to the East 
Coast, where I programmed on a 
free-lance basis for several years. 
Some of you probably remember 
that, in the 1960s, a programmer at a 
typical computer center needed to 
learn about nineteen languages in 
order to function adequately: JCL 
(Job Control Language); languages to 
control utilities and facilities, such as 
the linking loader; assembly language 
and the assembler's control language; 
plus several high-level languages and 
the methods for controlling their 
compilers. 

Listing 6 shows two of these 
languages, a PL/I program and the 
JCL necessary to run it. Note the 
obvious difference in syntaxes. 
FORTH developed in response to 
such conditions. In terms of modern 
FORTH, the importance of this exam- 
ple lies in the use of NEXT as a pro- 
cedure that goes off to get the next 
word and do something with it. 

Listing 7 shows a version of 
FORTH coded for the IBM 
System/360 with the routines PUSH 
and POP, which executed in about 
15 //.s. They include stack limit 
checking, which doubled the cost and 
was one of the things that led me to 
believe that execution-time stack 
checking is not desirable. This was 
coded in a macroassembler that did 
not have stack operations, which led 
to the deck full of statements like L19 



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Listing 4: An early version of the FORTH dictionary. 
8 PROCEDURE RELEVANCE; BEGIN REAL T,K0; 



9 


]:=0; I:= -1; WHILE WORD NEQ "END " DC 


180 


IF W = "= " THEN NEXT: =3 


1 


ELSE IF W = "GT 


" THEN NEXT: =4 


2 


ELSE IF W = "LT 


" THEN NEXT: = 5 


3 


ELSE IF W = "NOT 


" THEN NEXT: =6 


4 


ELSE IF W = "AND 


" THEN NEXT: =7 


5 


ELSE IF W = "OR 


" THEN NEXT: =8 


6 


ELSE IF W = " + 


" THEN NEXT: =9 


7 


ELSE IF W = "- 


" THEN NEXT: = 10 


8 


ELSE IF W = "* 


" THEN NEXT: = 11 


9 


ELSE IF W = 'V 


" THEN NEXT: = 12 


190 


ELSE IF K0:= SEARCH 1(W) GEQ THEN BEGIN 


1 


NEXT: = 1; NEXT 


= K:=K0 END 


2 


ELSE BEGIN 




3 


NEXT: =2; 




4 


IF BASE[K] = " " 


THEN NEXT:=WORDS[0] 


5 


ELSE NEXT:=W 


END; 


6 


NEXT:=0 END; 





Listing 5: An early implementation of the FORTH stack, written in BALGOL. 
7 BOOLEAN PROCEDURE RELEVANT; BEGIN 



I: 



9 

210 

1 

2 
3 
4 
5 
6 
7 



220 

1 
2 
3 



= ]:= -1; STACK[0]: = 1; 
J: = -l; 

STACK1J: =] + !]: 
STACK[J:=J+1]: 
STACK[J:=J-1]: 
STACK[J:=J-1]: 
STACK|I:=I-1]: 



DO CASE NEXT OF BEGIN 



= CONTENT; 

= NEXT; 

= REAL(STACK[I] = STACK[J + 1 ]); 

= REAL(STACK[J] GTR STACK[I+1]); 

= REAL(STACK[I] LSS STACK[J+1]); 



:REAL(NOT BOOLEAN(STACK[J))); 



STACK1I] 
STACK[J:=J-1]: 
STACK[J:=J-1): 
STACK[I:=J-1]: 
STACK[J:=I-1]: 
STACK[J:=J-1]: 
STACK[J:=I-1]: 
END UNTIL J LSS 0; 
RELEVANT: =BOOLEAN(STACK[0]) 



= REAL(BOOLEAN(STACK[I]) AND BOOLEAN(STACK[J+ 1])); 
= REAL(BOOLEAN(STACK[J]) OR BOOLEAN(STACK[J+ 1])); 
= STACK[J] + STACK[I + 1]; 
= STACK[J]-STACK[J + 1]; 
= STACK[J]xSTACK[J+l]; 
= STACK[I]/STACK[I+1]; 



END; 



DC AL2(*-L18), which gave me a link 
from L19 to the previous label. It 
worked but it was not pleasant. 

Listing 8 shows a similar routine, 
this time coded in COBOL. I am set- 
ting up a table of identified words 
that will be interpreted from an input 
stream. Since COBOL does not allow 
parameters for subroutines, it is 
awkward to do anything meaningful. 

New Concepts 

About this time, I began to think of 
defining a word that would define 
other words; and at that time, this 
idea was staggering. For example, 
{ ;CODE } was a very esoteric word. 
I explained it to people, but I could 
not express the potential I thought it 
had. 

It took time to find out exactly 
what { ,CODE } should do (it 
specified the code to be executed for a 
previously defined word). I do not 
have the records, but I think the ini- 
tial code for { ;CODE } was three or 
four lines long; to simplify that code 



was one of the driving forces behind 
the address interpreter — to make it 
possible to code { ;CODE } cleanly. 
This had implications as to what 
registers should be available. 

The fact that W should be saved in 
a register for defining words led to 
indirect, rather than direct, threaded 
code. That was the most complicated 
concept I had coded in this evolving 
program — probably deserving of a 
patent in its own right. 

A little bit later, it seemed that 
there ought to be an analog of 
{;CODE } that specified the code to 
be interpreted when you executed a 
word. It seemed the natural balance, 
but when the idea first arose, I did not 
have the foggiest notion of what to do 
or what the implementation should 
be. The first definition of this analog, 
called { ;: } (semicolon-colon), 
required three or four lines of code. It 
had to do what { ;CODE } did, and 
then more. 

Out of that came the distinction 
between compile-time action and 



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execute-time action. It was conve- 
nient for words to be coded to act this 
way, but it was expensive. It required 
not only the address of the code to be 
executed, but the address of the code 
to be interpreted, as well as the 
parameter to be supplied to the code 
being interpreted so you could do 
something useful. 

Late in the 1960s I went to work for 
Mohasco Industries, where I put 
something strongly resembling 
FORTH on a Burroughs 5500, cross- 
compiled to the 5500 from an IBM 
1130. (There is no assembler on the 
5500; there is a dialect of ALGOL 
called SBOL that Burroughs used to 
compile operating systems, not 



available to users.) Listing 9 shows 
the code definitions of stack opera- 
tions on the 5500, which was a stack- 
oriented processor at a time when 
stack machines were not popular. 
The names of some FORTH stack 
operators stem from that machine's 
operations; see, for example, DUP . 
The symbol <t stands for CODE and 
distinguishes the assembler's OR from 
the FORTH OR . (Vocabularies were 
not yet available.) 

Listing 10 gives an example of 
FIND (a dictionary search routine) 
coded for the 5500. Notice the word 
SCRAMBLE , a colon definition mak- 
ing a hashed search. Apparently I had 
eight threads to the dictionary here, a 



Listing 6: The NEXT procedure in PL/I and its associated ]CL (Job Control Language) 
statements (lines 1 thru 8). 



1 //UTILITY 

2 

3 

4 

5 

6 

7 



//SYSUT2 

II 

II 

//SYSIN 

./ 



DD 



DD 
ADD 



9 
10 
1 
2 
3 
4 
5 
6 
7 
8 
9 
20 
1 
2 
3 
4 



JOB SYSTEM, OVERHEAD 
EXEC PGM = IEBUPDTE,PARM = NEW 
//SYSPRINT DD SYSOUT = A 

DSNAME = OUTLIB,UNIT = 2314, DISP = (NEW, KEEP), 
VOLUME = SER = MOORE, SPACE = (TRK,( 100, ,10)), 
DCB = (RECFM = F,LRECL = 80.BLKSIZE = 80) 
DATA 

NAME = WORD.LEVEL = 00,SOURCE = 0.LIST = ALL 
DECLARE KEYBOARD STREAM INPUT, PRINTER STREAM OUTPUT PRINT; 
NEXT: PROCEDURE CHARACTER^); 
DECLARE (1 TEXT CHARACTER(81) INITIAL((81)" "), 

2 C(81) CHARACTER(l), I INITIALED, W CHARACTER^), 
WORD CHARACTER(32) VARYING BASED(P),P, NUMERIC BIT(l)) EXTERNAL; 
DO WHILE C(I) = " "; 1 = 1 + 1; 
IF 1=82 THEN BEGIN; 1 = 1; 

READ FILE(KEYBOARD) INTO(TEXT); END; END; 
P = ADDR(C(I»; 

IF C(I) = "-" OR C(I) = "." OR "0" LE C(I) THEN BEGIN; NUMERIC = "1"B; 
IF C(I) NOT = "." THEN DO 1 = 1 + 1 BY 1 WHILE "0" LE C(I); END; 
IF C(I) = "." THEN DO 1 = 1 + 1 BY 1 WHILE "0" LE C(I); END; END; 
ELSE DO; NUMERIC = "0"B; 

IF "A" LE C(I) THEN DO 1 = 1+1 BY 1 WHILE "A" LE C(I) OR C(I) = "-"; 
END; ELSE 1 = 1 + 1; END; 
W = WORD; RETURN(W); 



Listing 7: The FORTH words PUSH and POP written in IBM 360 assembly language. 



0056 



00 




400004 




5AC0 6014 


00014 


5040 C000 


00000 


19CB 




0729 




47F0 667C 


0067C 


001A 




0444D2CF50400008 




41 CO C004 


00004 


5840 C004 


00004 


4 1C0 C004 


00004 


59C0 602C 


0002C 


07C9 




47F0 667C 


0067C 



830 L18 DC AL2C-L17) 

831 NAME 3,X'445550',0 DUP 
832+ DC AL1(3),X'445550' 
833 + DC X'0' 

834+ ORG *-2-V0 

835+ DS OH 

836+ ORG * + V0+l 

837+ DC AL1(0*X V 40' + X'40'),AL2(4) 

838 PUSH A SP.MFOUR COSTS 15 US 

839 ST T,0(,SP) 

840 CR SP,DP 

841 BCR 2, NEXT BHR 
842 B ABORT 

843 L19 DC AL2C-L18) 

844 DC AL1(4),X , 44D2CF50',X'40',AL2(8) DROP 

845 LA SP,4(,SP) 

846 POP L T,4(,SP) COSTS 21 US 

847 LA SP,4(,SP) 

848 C SP, SP00 

849 BCR 12, NEXT BNHR 
850 B ABORT 



concept we added back to FORTH 
when we developed polyFORTH last 
year. 

FORTH and the IBM 1130 

At Mohasco I also worked directly 
on an IBM 1130 interfaced with an 
IBM 2250 graphics display. The 1130 
was a very important computer; it 
had the first cartridge disk, as well as 
a card reader, a card punch (as 
backup for the disk), and a console 
typewriter. The 1130 let the program- 
mer, for the first time, totally control 
the computer interactively. 

FORTH first appeared as an entity 
on that 1130. It was called 
F-O-R-T-H, a five-letter abbreviation 
of FOURTH, standing for fourth- 
generation computer language. That 
was the day, you may remember, of 
third-generation computers and I was 
going to leapfrog. But because 
FORTH ran on the 1130 (which per- 
mitted only five-character 
identifiers), the name was shortened. 

What came out of the 1130 was a 
cross-assembler that assembled the 
instructions, which were then to be 
executed by the 2250. I think the 2250 
had its own memory, and these things 
had to be programmed carefully. 
What I accomplished was that the 
1130 in FORTRAN in 32 K bytes 
could draw pictures on the 2250, fair- 
ly slowly; and FORTH, in 8 K bytes, 
could draw three-dimensional mov- 
ing pictures on the 2250 — but it could 
do that only if every cycle was 
accounted for and if the utmost was 
squeezed out. That is why 
FORTRAN had to go— I required an 
assembler and could not do an 
impressive enough job with FOR- 
TRAN. 

But high-level or colon definitions 
were not yet compiled — the compiler 
came much later. The text was stored 
in the body of the definition, and the 
text interpreter reinterpreted the text 
in order to discover what it was to 
do. This contradicts the efficiency of 
the language, but I had big words that 
put up pictures and I did not have to 
interpret too much. The cleverness 
was limited to squeezing out 
extraneous blanks as a compression 
medium. I am told that this is the way 
that BASIC acts today in many 
instances. 

This machine had a disk drive, and 
I am almost certain that the word 
BLOCK existed in order to access 



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records off the disk. I do remember 
that I had to use the FORTRAN I/O 
(input/output) package and that it 
would not put the blocks where I 
wanted them; it put the blocks where 
if wanted them, and I had to pick 
them up and move them into my buf- 
fers. 

At Mohasco I also implemented 
FORTH on a Univac 1108, interfacing 
it with their COBOL compiler. 
Listing 11 displays a set of record 
descriptions in a Dun and Bradstreet 
reference file (for looking up bad 
debts). The layout shows named 
fields followed by the number of 
bytes allocated. 

The Mohasco programs mark the 
transition point between something 
that could be called FORTH and 
something that could not. All the 
essential features except the compiler 
were present by 1968. 

The First Modern FORTHs 

The first modern FORTH was 
coded in FORTRAN. Shortly 
thereafter it was recoded in 
assembler. Much later it was coded in 
FORTH. It took a long time before I 
thought that FORTH was complete 
enough to code itself. The first thing 
to be added to what had already 
existed was the return stack. That 
was an important development; the 
recognition that there had to be exact- 
ly two stacks, no more, no less. 

The next thing to be added was 
even more important — the full- 
fledged dictionary, that is, the dic- 
tionary in the form of a linked list. Up 
until then, flags had been set or com- 
puted GO TOs had been executed to 
provide some mechanism for asso- 
ciating a subroutine with a word. The 
replacement of all that by a code file 
containing the address of the routine 
made an incredibly fast way of 
implementing a word once it was 
identified. 

The first use of modern FORTH 
occurred when it was written for a 
Honeywell H316 at the NRAO (Na- 
tional Radio Astronomy Observ- 
atory). In 1971 1 was hired by George 
Conant to write a radio-telescope 
data-acquisition program: that led to 
the next step, the compiler. This 
meant the recognition that, rather 
than reinterpret a string of text, 
words could be compiled and an 
average of 5 characters per word 
could be replaced by 2 bytes per 
word. This gave a compression factor 



1 


MOVE 


2 


MOVE 


3 


MOVE 


4 


MOVE 


5 


MOVE 


6 


MOVE 


7 


MOVE 


8 


MOVE 


9 


MOVE 


70 


MOVE 



Listing 8: A structured table routine, in COBOL. 



"CONFIGURATION" TO IDENTIFY(4); 
"DATA" TO IDENTIFY(5); 
"FILE" TO IDENTIFY(6); 
"FD" TO IDENTIFY(7); 
"MD" TO IDENTIFY(B); 
"SD" TO IDENTIFY(9); 
"WORKING-STORAGE" TO IDENTIFY(IO); 
"CONSTANT" TO IDENTIFY(ll); 
"PROCEDURE" TO IDENTIFY(12); 
"INPUT-OUTPUT" TO IDENTIFY(13); 



Listing 9: Code definitions of FORTH stack operations on the Burroughs 5500, written 
in SBOL. 

LIST 

0001 ( "PRIMITIVES' 26 LAST = 30 SIZE = ) 

0002 c = _S RETURN 

0003 « @ <SD RETURN 

0004 <f + V 241, RETURN 
0005 

0006 C OR tOR RETURN 

0007 <t AND «AND RETURN 

0008 <t NOT 115, RETURN 

0009 « DUP «DUP RETURN 
O00A « SWAP <tSWAP RETURN 
000B <t DROP CDROP RETURN 
000C <t + +1 RETURN 

000D t - -1 RETURN 

000E * MINUS CMINUS RETURN 

000F * * *1 RETURN 

0010 <t / /l RETURN 

0011 n MOD <tMOD RETURN 



Listing 10: A dictionary search routine, FIND , written for the Burroughs 5500. 

0013 <tSM TFIND SCRAMBLE <SD eDUP 

0014 41 >A 41 >B eBEGIN V <U 1771, <fIF 

0015 <tBEGIN V0 <U 1771, *IF 

0016 1 <L RESULT 

0017 cTHEN _ADDR «DUP 1 <L <S 

0018 OS WORD <U tEQUAL «IF 

0019 VI _U OS RESULT 

001 A CTHEN CDUP <SD CBACK 

001B <tTHEN GET "tBACK 

001C : FIND TOP 0FIND <tIF UR < UD <tB tTHEN; 



Listing 11: Prototype of a file layout, running under FORTH on a Univac 1108. This 
version of FORTH was written in COBOL. 

3 DBI DBI/MOORE 33 33 

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of 2 or 3, not drastic but appreciable. 
But execution speed would be much 
faster. Again I asked myself, as I had 
done when I first began modifying 
programs: if it was that easy, why 
hadn't anyone else done it? It took me 
a long time to convince myself that 
you could compile anything and 
everything. 

Interrupts came around this time. It 



was important to utilize the interrupt 
capability of the computer, but it had 
not been done by me before that — I 
did not know anything about inter- 
rupts. I/O, however, was not yet 
interrupt-driven. Interrupts were 
available for the application if it 
wanted them — FORTH did not 
bother. 

The multiprogrammer came along 



84 August 1980 © BYTE Publications Inc 



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a couple of years later when we 
developed an improved version of the 
system for NRAO's telescope at Kitt 
Peak. This computer was a PDP-11; 
the multiprogrammer had four tasks. 
Input was still not interrupt-driven, 
which was unfortunate. 

The Second FORTH Programmer 

Ten years ago there was one 
FORTH programmer, me. The se- 
cond FORTH programmer, Elizabeth 
Rather, came along in 1971. That is 
quite a quantum jump, from one to 
two; the next step was four (the next 
two came out of Kitt Peak National 
Observatory); the growth can be 
traced from there to the several thou- 
sand today. 

The first FORTH user was Ned 



Conklin, head of the NRAO station 
at Kitt Peak, Arizona. NRAO runs a 
millimeter-wave radio telescope that 
is in great demand by observers, in 
part because it is responsible over the 
last 10 years for discovering half of 
the interstellar molecules that are 
known to exist. FORTH is still run- 
ning on that telescope at Kitt Peak 
and on a lot of other telescopes. 

Given interest from other 
astronomers, a few believers split off 
from NRAO in 1973 and formed 
FORTH Inc. We were deluged by 
requests for FORTH systems from 
astronomers and went into business 
to try to exploit that market. It would 
still be our principal line of business 
today except that there are so few 
new telescopes in the world that you 



Listing 12: Field and record layouts for a recent FORTH Inc data-base management 
system. 

64 LIST 

( GLOSSARY FILE) 

1 2 ( LINK) 12 BYTES WORD 12 BYTES VOC 

2 NUMBER SOURCE NUMBER STACKS 70 BYTES PHRASE 

3 210 FILLER ( 4 LINES) 32 FILLER ( 340 B/R, 3/BLOCK) DROP 

4 2 24 BYTES WORD + VOC DROP 




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market. 

We developed miniFORTH™ 
(FORTH on minicomputers) with the 
idea of having a programming tool. 
An important implementation of the 
tool came when we put an LSI-11 and 
FORTH into a suitcase. I think I 
became the first computer-aided 
programmer — computer-aided in that 
I had my computer and took it 
around with me. I talked to my com- 
puter, my computer talked to your 
computer, and we could com- 
municate much more efficiently than 
I could communicate directly with 
your computer before it could run 
FORTH. Using this tool, we have put 
FORTH on many computers. 

We added the feature of interrupt- 
driven I/O when FORTH Inc pro- 
duced its first multiterminal system. 
It did not speed things up particularly 
from the user's point of view, but it 
did prevent any loss of characters 
when several people were typing at 
the same time. You did not have to 
look quickly to get the character 
before the next one came along. They 
were all buffered and waiting for you, 
which is an important distinction for 
multiprogrammed systems. 

Data-base management came along 
at this time. It has been extensively 
changed, just as FORTH has. But fun- 
damentally, nothing has changed. 
The concept of files, records, fields, 
and relational pointers that 
polyFORTH™ offers dates back from 
1974 or so — years and years ago. 
Listing 12 shows a recent application 
of the FORTH Inc data-base manage- 
ment system. 

With microFORTH™ in 1976 came 
the first version of our current target 
compilers. They are very complex 
things, much more so than I expected 
them to be. At about the same time, 
we worked out the current implemen- 
tation of DOES> . 

This new form of { ;: } does not 
require the address of the code to be 
interpreted. Since that is supplied by 
a different mechanism, the parameter 
can occupy the parameter field as it is 
supposed to. You can "tick" it and 
change its value, which is nice. [The 
FORTH word { ' } (called "tick" 
above) places the address of the word 
that follows it onto the stack.... GW] 
But we save 2 bytes for every 
DOES> word, 2 bytes for very com- 
mon words — and for 3 years, we did 



86 August 1980 © BYTE Publications Inc 



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not realize that we had missed the 
optimum by so much. 

I know no way of speeding this 
process from initial thought to 
development, except to let a certain 
amount of time pass. We could sit, 
we did sit and debate this thing 
endlessly, and we missed the obvious. 

I think that completes the 
capabilities that I think of as FORTH 
today. You see how they dribbled 
in — at no point did I sit down to 
design a programming language. I 
solved the problems as they arose. 
When demands for improved perfor- 
mance came along, I would sit and 
worry and come up with a way of 
providing improved performance. 

polyFORTH is a condensation of 
everything that we at FORTH Inc 
have learned in the last 10 years of 
developing FORTH. I think it is a 
very good package. I foresee no fun- 
damental changes in the design of the 
language except for accommodation 
to FORTH standards, which are 
becoming increasingly important. 

Implementations of FORTH 

I would like to review the 
implementations of FORTH of which 
I am aware. It is actually a tour 
through the history of computers and 
it is fascinating that this could all 
have happened in 10 years. 

FORTH has been programmed in 
FORTRAN, ALGOL, PL/I, COBOL, 
assembler, and FORTH; and I am 
sure some of you can come up with 
other languages with the same 
history. My list is strictly personal. 

FORTH has been implemented on 
the Burroughs 5500; the IBM 1130; 
the Univac 1108; the Honeywell 316; 
the IBM 360; the Data General Nova; 
the HP 2100 (not by me but by Paul 
Scott at Kitt Peak); the PDP-10 and 
PDP-11 (by Marty Ewing at the 
California Institute of Technology); 
the PDP-11 (by FORTH Inc); the 
Varian 620; the Mod-Comp II; the 
GA SPC-16; the CDC-6400 (by Kitt 
Peak); the PDP-8; the IV-Phase; the 
Computer Automation LSI-4; the 
RCA 1802; the Honeywell Level 6; 
the IBM Series 1; the Interdata; the 
6800; the 8080; the 8086; the TI-9900; 
and soon the 68000, the Z8000, the 
6809, and a Child Inc computer. 
Some independent groups have 
6502s, ILLIAC, and others running 
FORTH. I raise the question — is it the 
case that FORTH has been put on 



every computer that exists? 

Some people think FORTH ought 
to be machine independent, but that 
premise is wrong. The equivalence is 
FORTH — each machine requires 
meticulous attention to its individual 
characteristics. You must use all the 
hardware capabilities of each 
machine and must then work to force 
it into the mold specified by FORTH's 
virtual machine. 

For example, we put a subset of 
FORTH on an SMS-300 microcom- 
puter. It had only eight instructions. 
The internal characteristics of every 



At no point did I sit 
down to design a pro- 
gramming language. I 
solved the problems as 
they arose. 



machine can and must be exploited. 
You do not need any particular 
number of registers or stacks or 
anything. All can be simulated, but if 
you neglect the abilities of the 
machine, you can end up a factor of 2 
down in performance from where 
you might otherwise be. 

FORTH-in-Hardware Computers 

The first FORTH computer I know 
of was built at Jodrell Bank in 
England around 1973. It is a redesign 
of an English Ferranti computer that 
went out of production. The obser- 
vatory at Jodrell Bank was going to 
build their own bit-slice version; they 
discovered FORTH about the same 
time, modified the instruction set to 
accommodate FORTH, and built 
what I am told is a very fast FORTH 
computer. I have never seen it, but 
have talked to its competent designer, 
John Davies, who is one of the early 
FORTH enthusiasts. 

In 1973, before Dean Sanderson 
came to FORTH Inc to develop 
microFORTH, he had a FORTH com- 
puter at a company called General 
Logic. It qualifies as a FORTH com- 
puter because it has a FORTH 
instruction. And there is a story 
there. Dean showed me his instruc- 
tion set, and there was this funny 
instruction that I could not see any 
reason for — I figured it was some 
kind of no-op or catchall or 



something; it had the weirdest pro- 
perties, and it could not possibly be 
useful. It was NEXT. It was a one- 
instruction NEXT which was 
beautiful. And it was a very simple 
modification (this was a bit-slice com- 
puter) to the instruction set — a few 
wires here and there — and that is the 
first time I saw a FORTH computer, if 
you will. I call it a FORTH computer 
because it had the ability to change 
itself from an ordinary computer into 
a FORTH computer. 

I think that hardware today is in 
the same shape as software was 20 
years ago. No offense, but it is time 
that the hardware people learned 
something about software. There is 
an order or two of magnitude 
improvement in performance possible 
with existing technology. We do not 
need picosecond computers to make 
really substantial improvements in 
execution speed. Faced with that 
realization, there is no point in trying 
to optimize the software any further 
until we have taken the first crack at 
the hardware. The hardware redesign 
has to be as complete as the software 
redesign was. The standard micro- 
processors did not have FORTH in 
mind. Those minicomputers that can 
be microprogrammed cannot be 
microprogrammed well enough to 
even be worth doing. The improve- 
ments available are much greater 
than you can achieve by these half 
measures. 

I have built a small FORTH com- 
puter. The design changes as fast as 
the chips can be plugged into the 
board. But it is not difficult to do. 
Here are the characteristics of a 
FORTH computer: 

• It does not need a lot of memory 
(16 K bytes is about right — half 
programmable read-only memory, 
half user programmable memory, 
maybe). 

• It does not need a lot of I/O ports; 
in fact, it does not need any I/O 
ports except for the application 
requirements. 

• A serial line and interface to a disk 
drive are useful but not required. 

We have put FORTH on an 
8080-based machine with a virtual 
disk in memory, enough memory to 
hold eight blocks. The system is quite 
viable and has no particular problem 
with system crashes. Bubble 



88 August 1980 © BYTE Publications Inc 



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memories are coming. A FORTH 
computer does not need much mass 
storage; 100 K bytes are adequate, 
and 250 K bytes are plenty. The fact 
that FORTH can exist quite happily 
on a machine that is very small by 
contemporary standards should be 
exploited. 

Organizations 

Finally, I would like to run through 
the history of the organizations that 
have been involved with FORTH. 
They have formed another thread of 
the tapestry. It began with Mohasco, 
of course, followed by NRAO and 



Kitt Peak National Observatory: then 
came FORTH Inc. 

The next step was probably 
DECUS (Digital Equipment Com- 
puter Users' Group). Marty Ewing 
gave his PDP-11 FORTH system to 
DECUS. FORTH Inc was not sure 
whether free FORTHs floating 
around was a good idea at the time. 
But it turned out that a lot of people 
were exposed to FORTH who other- 
wise would not have been. 

Cybek came along and provided an 
entry into the business-systems 
market. Art Gravina, the president of 
Cybek, is the person who designed 



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our data-base management system. 
He provided us the opportunity to do 
commercial systems and the ability to 
handle ten times as many terminals as 
he could with the BASIC program 
that preceded it. 

In about 1976, a committee of the 
International Astronomical Union 
met and adopted FORTH as a stan- 
dard language. That was a boost in 
the world of astronomy, although the 
world of astronomy was no longer 
the major driving force in the 
popularity of FORTH. 

I think EFUG (the European 
FORTH Users' Group) came along 
about that time (1976). It turned out 
to our surprise that Europe was a 
hotbed of FORTH activity that we 
were largely unaware of (and perhaps 
still are, in that we are not involved in 
that world and do not appreciate the 
level of interest). An international 
FORTH Standards Team probably 
grew from their first meetings. A cou- 
ple of years later, the FORTH Interest 
Group started. Now we have 
FORML — FORTH Modification 
Laboratory, an idea-generating 
organization. 

Conclusion 

The tendency seems to be for peo- 
ple to organize themselves in groups. 
Some of these groups are companies, 
others are associations. It looks like 
FORTH is going to be a communal 
activity in that sense — that it will 
grow from the work of unstructured 
clusterings of like-minded people. 
The suggestion is that this whole 
world of FORTH is going to be quite 
disorganized, uncentralized, and 
uncontrollable. It's not bad, perhaps 
it's good. 

My view of the future is more 
unsettled today than it has been for 
years: promising, confusing, perplex- 
ing. The implications are perhaps as 
staggering now as they were 20 years 
ago. The promise of realization is 
much higher. My original goal was to 
write more than forty programs in 
my life. I think I have increased my 
throughput by a factor of 10. I do not 
think that that throughput is 
program-language limited any 
longer. So I have accomplished what 
I set out to do: I have a tool that is 
very effective in my hands. It seems it 
is very effective in others' hands as 
well. I am happy and proud that this 
is true. 



90 August 1980 @ BYTE Publications Inc 



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Components of FORTH 

FORTH is characterized by five major elements: dic- 
tionary, stack, interpreters, assembler, and virtual 
memory. Although not one of these is unique to 
FORTH, their interaction in FORTH produces a 
synergistic effect that creates a programming system of 
unexpected power and flexibility. 

• Dictionary: The resident FORTH system is 
organized into a dictionary that occupies almost 
all of program memory. The dictionary is a 
threaded list of variable-length items, each of 
which defines a word of the vocabulary. The 
actual content of each definition depends on the 
type of word: noun, verb, etc. The dictionary is 
extensible, growing toward high memory. In a 
multiterminal system, terminal tasks may have 
private dictionaries that are connected in a 
hierarchical tree structure. 

• Stack: Two push-down stacks (last-in, first-out, 
or LIFO, lists) are maintained for each 
multiprogrammed task in the system. These pro- 
vide the primary communication between 
routines as well as an efficient mechanism for 
controlling logical flow. A stack normally con- 
tains items one computer word long, which may 
be addresses, numbers, or other objects. Stacks, 
which are of indefinite size, grow toward low 
memory. 

• Interpreters; FORTH is fundamentally an inter- 
pretive system, meaning that program execution 
is controlled by data items rather than by 
machine code. It is a common assumption that 
interpreters are severely wasteful of processor 
time; this is avoided in FORTH by maintaining 
two levels of interpretation. 

The first of these is the text interpreter, also known 
as the outer interpreter. It works in a conventional 
manner, parsing text strings that come from terminals 
or mass storage and looking up each word in the dic- 
tionary. When a word is found in the dictionary, it is 
executed (unless the task is in compile mode) by invok- 
ing the address interpreter. 

The address interpreter (also known as the inner 
interpreter) interprets strings of absolute memory 
addresses by executing the definition pointed to by 
each. Most dictionary definitions contain addresses of 
previously defined words that are to be executed by 
this interpreter. This level of interpretation requires no 
dictionary search since these words have already been 
compiled by the text interpreter, which generated the 
absolute addresses. 

The address interpreter has several important pro- 
perties. First, it is fast. Indeed, on some computers it 
executes only one instruction for each word, in addi- 
tion to the code implied by the word itself. Second, it 
interprets compact definitions. Each word referenced 
in a definition compiles a single memory location. 
Finally, the definitions are machine independent 
because the definition of one word in terms of others 
does not depend upon the computer that interprets the 
definitions. 



• Assembler: FORTH includes a resident 
assembler, which allows the programmer to 
define words that will cause specified machine 
instructions to be executed. This type of defini- 
tion is necessary to perform device-dependent 
input and output operations, to implement 
elementary operations, and to do highly time- 
critical processing. 

• Virtual memory: The final key element of 
FORTH is its blocks: fixed-length segments of 
disk space that may contain program text or 
data. A number of buffers are provided in 
memory; blocks are read into them automatical- 
ly when referenced. If a block is modified in 
memory, it is automatically replaced on disk. Ex- 
plicit read and write operations, therefore, are 
not required; programmers may presume that 
program text or data is in memory whenever it is 
referenced. 

[The above paragraphs present a concise overview 
of FORTH as a language; the following paragraphs 
describe features of a FORTH Inc product, 
polyFORTH...GW] 

The standard polyFORTH system utilities include 
the following: 

Text editor: Facilitates editing program source 

text, both by line and by 
character. 

Source listings: Prints program source listings and 
indexes. 

Disk copy: Provides for disk-to-disk copying 

of data file and program source 
files for backup purposes. 

Disk diagnostic: Produces a simple, read-only disk 
diagnostic that may be run at any 
time without disturbing other 
users. (More extensive hardware 
diagnostics are optional.) 

Each polyFORTH system also contains a Target 
Compiler capability; this allows the user to develop, 
for run-time applications only, a computer system that 
does not require the entire operating system. Since 
FORTH is an interpretive language, an interpreter 
must always be present; but the target compilation 
process creates the minimum dictionary necessary, 
thus allowing a program to be run with a minimum of 
memory overhead. Typically, this overhead is less 
than 1000 bytes. 

Full data-base management support is available in 
an optional Extended File Management package. In- 
cluded within its structure are the essential features of 
the CODASYL standard along with the characteristic 
speed, compactness, and flexibility of the FORTH 
language. Facilities include commands for file defini- 
tion and formatting and for field and record descrip- 
tions, as well as several file-accessing techniques, 
operators for accessing individual fields by name and 
fields within specified files, and such utility functions 
as a report generator and an optional key-sort 
routine. ■ 



92 August 1980 © BYTE Publications Inc 



Circle 61 on inquiry card. 



^ 




BASIC SOFTWARE LIBRARY 

NOW • 10 * Volumes and Growing 

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WHY Pay hundreds of dollars for Software that does Not work when WE offer the BEST 
available Software for only a few dollars a program. And what is better OURS WORKS! 

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in Volume III for over $6,000 but a few years ago we decided to promote software to the mass public and it was an 
instant success. 

For Homeowners, Businessmen, Engineers, Hobbyists, Doctors, Lawyers, Men and Women 



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Astronaut 


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The disk programs in Volumes VI, VII and X are 
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OVER 116,000 IN USE TODAY 



BYTELINES 

NEWS AND SPECULATION ABOUT PERSONAL COMPUTING 




Conducted by Sol Libes 




Aersonal Computer 


market, prices must 


memory) and to have 


announcing products long 


Prices Increasing: Both 


decrease, not increase. The 


changed the copyright 


before they will be 


Texas Instruments (TI) and 


experts are therefore 


notice. Nestar is taking ac- 


available in production. 


Atari recently announced 


disturbed over what they 


tion in this case. 


This will, no doubt, have 


price increases for their 


feel will be a real damper 


This type of software 


an impact on sales of the 


personal computer 


to personal-computing 


piracy will have a more 


Zilog Z8000 and Motorola 


systems. Radio Shack, 


sales. 


serious financial impact on 


MC68000, as purchasers 


Commodore, and Apple 




the software vendor than 


may now wait for a more 


are holding the line, at 


Ooftware Piracy: Over 


hobbyist copying. Here, 


powerful product. 


least for the present. 


the vendor is actually los- 


The 32-bit micro- 


Atari increased the price 


the years, software vendors 


ing dealer sales, since 


processor will be known as 


of its Model 400 from $550 


have complained many 


many dealers are purchas- 


the iAPX-432, and will be a 


to $630 and the Model 800 


times about hobbyists copy- 


ing the software from the 


3-chip set with a brand-new 


from $1000 to $1080. The 


ing software from one 


pirate at a much lower 


architecture and instruction 


company attributed the in- 


another instead of buying 


cost — and probably mark- 


set. Intel claims that it will 


crease to rising component 


it. One supplier even has 


ing it up more — than if the 


provide the power of a 


costs, particularly com- 


gone so far as to offer a 


dealer purchased it from 


medium-scale IBM 370 


ponents that incorporate 


$10,000 reward for informa- 


the legitimate vendor. In 


system. It will directly ex- 


precious metals. 


tion leading to the convic- 


most instances, end users 


ecute Ada code. Ada is an 


TI, on the other hand, 


tion of anyone found copy- 


are not aware that they 


upward extension of Pascal, 


has subtly unbundled the 


ing its software. I am not 


have purchased a pirated 


and it is the language 


99/4 system. Previously, a 


aware that this plan has 


copy until they try to get 


designed for and to be 


purchaser bought the key- 


had any positive results. It 


software support from the 


used by the US Department 


board/processor console 


has, however, raised the ire 


rightful vendor. 


of Defense. It is interesting 


and a 13-inch color video 


of many hobbyists, and 




to note that at this time 


monitor for $1150. Now he 


there may have been a 


X ektronix Sets Up 


there is no Ada compiler 


can buy the console for 


negative effect on this par- 


up and running. 


$950 and the monitor for 


ticular supplier's software 


Handicapped Person's Hot 


The two new 16-bit 


$450, a total of $1400. Or, 


sales, because he sells 


Line: Physically handicap- 


microprocessors are essen- 


he can buy the console and 


cassette software mostly to 


ped persons, or people 


tially 8086s with integrated 


an RF (radio-frequency) 


hobbyists. 


wanting information on 


functions and higher speed 


modulator ($75) and hook it 


Although copying by 


special electronic equip- 


to improve performance. 


up to a standard color 


hobbyists remains a prob- 


ment for coping with 


They are intended for 


television set. This com- 


lem for software vendors, a 


physical impairments, can 


multiprogram and multi- 


bination costs $1025, which 


much greater problem has 


get answers to questions by 


user systems. 


is only $125 less than the 


developed: software piracy 


calling the Tektronix 


Intel promises that all 


old complete system price. 


for commercial purposes, 


Special Interest Group on 


three new microprocessors 


Although Radio Shack, 


by pirate vendors who are 


Computers and the 


will be available in 1981, 


Commodore, and Apple 


marketing copies in much 


Physically Handicapped in 


with the 32-bit micro- 


have not raised the prices 


the same way as audio- and 


Beaverton, Oregon, at 


processor becoming 


of their basic systems, cer- 


videocassette pirates do. 


(503) 357-4354. 


available first. 


tain peripheral devices and 


For example, Nestar 






add-ons have increased in 


Systems of Palo Alto, 


Xntel Releases Data on 


*Xerox Opens Computer 


price. Furthermore, when 


California, has charged 


the Federal Communica- 


that its read-only-memory- 


32-Bit Microprocessor: 


Stores: The Xerox Corpora- 


tions Commission (FCC) 


based "Basic Programmer's 


Intel, the recognized leader 


tion recently opened retail 


RF-radiation standards go 


Toolkit" (for the Com- 


in microprocessor develop- 


stores in Dallas, Texas, and 


into effect on January 1, 


modore PET) is being 


ment, has "leaked" ad- 


Denver, Colorado. Ap- 


1981, there may be signifi- 


distributed in Europe in 


vanced information on 


parently these are the first 


cant price increases. 


both cassette and floppy- 


three new forthcoming 


links in a chain of retail 


Most personal-computer 


disk format. The pirating 


16- and 32-bit micropro- 


computer stores across the 


marketing experts agree 


distributor is alleged to 


cessors. Intel is now play- 


country. The store is selling 


that for personal computing 


have changed the code 


ing the game of trying to 


Xerox 510 small-business 


to become a true mass 


(relocating it into user 


scoop its competition by 


computers, Apple II com- 










c«*' 



^ 







3-DA/v7M>\r£D 
SOLOfl GRAPHICS 
The Program made 
famous on 
National TV! 

FOR 48K APPLE 1 1 
COMPUTERS WITH DISK 

APPLE WORLD turns your Apple into a sophisticated graphics 
system capable of creating animated three-dimensional color 
images, projecting them in true perspective on the screen, rotate 
them, move them closer, further away, and many other exciting and 
imaginative things. 

A powerful screen-oriented text editor is included to facilitate 
image formation. This program was recently featured on Tom 
Snyder's Prime Time Saturday TV Show and is now available for 
sale. 

APPLE WORLD'S powerful editor is so easy to use that children will 
love it. You can now "sketch" your dream house, boat, car. or 
fantasy empire. Then view it as it would be seen from 10.000 feet, or 
you can ZOOM in until the screen is filled with a doorknob. You 
could then go inside and move from room to room examining 
furniture placement as your screen rotates within the room. I mages 
or specific parts of images can easily be saved to disk or printer. 

Does all this sound I ike science fiction? You won't think so after you 
have visited Apple World. 

Introductory Price $59.95 

36 page manual included 

Look for the RED-WHITE-BLUE 
United Software Display at your local 
computer dealer, or send check or 
moneyorder, plus $3.00 shipping to: 

i= UNITED 
^5 SOFTWARE 
OF 

750 3RD Avenue, AMERICA 

New York NY 10017 

(212) 682-0347 Telex 640055 

DEALER INQUIRIES INVITED 




KEYED 

RANDOM 

ACCESS METHOD 

Many times more powerful and efficient than the primative "relative 
record" method used by Apple & Commodore. 

FOR APPLE II & COMMODORE PET 

KRAM is the FASTEST and MOST POWERFUL keyed access 
method available for the Apple & Commodore CBM (Pet) 
Computers. Written entirely in 6502 machine code. KRAM is 
extremely fast, comprehensive in scope, very compact, and easy to 
use. KRAM function calls are invoked via a single instruction. 

Using the sophisticated capabilities of KRAM the Apple& CBM (Pet) 
can now fully meet the requirements of information management 
applications, such as: Accounts Receivable/Payable. Inventory 
Control, General Ledger, Payroll, Mailing lists, and Database 
Management. Programs can now be 30% to 90% shorter and run 
many times faster! Less experienced users can now create powerful 
programs! 



KRAM Release 2.0 Functions: 

• Create/Open a dataset 

• Put record by Key 

• Add & delete records by Key 

• Get any record by Full/Partial 
key in 4/10ths of a second 
(2/10ths with Corvus Disk) 



Supports multiple disks 
Read next or previous record 
Dynamic space allocation 
Dynamic space reclamation 
Dynamic index compression 
Never needs file 
reorganization! 



An 87 page manual fully documents KRAM 2.0 detailing KRAM 
functions and illustrating with programming samples. KRAM 
architecture is fully explained and a sample mailing list application 
program is included. 

PET & Apple Requirements 

KRAM is designed to work with both Apple's Disk II, or Corvus 
Systems 10 Megabyte Winchester Disk, and Commodores 2040, 
3040, and 8050 Disk units. KRAM 2.0 requires an integer Apple or 
Apple Plus with integer card and at least one disk drive. KRAM 
works on any 40/80 column 16K/32K PET. 

Introductory Special $99.95 

FOR COMMODORE 16K/32K COMPUTERS 
DATABASE MANAGEMENT SYSTEM — A comprehensive, 
interactive system like those run on mainframes! Six modules 
comprising 42K of programming allow you to; create, edit, delete, 
display, print, sort, merge, etc., etc. - databases of up to 10,000 
records. Printer routines automatically, generate reports and labels 
on demand. 60 pages of concise documentation are included. 
Requirements - 16-32K PET and 2040 Dual Disk (printer 
optional) COST $125 



OTHER SOFTWARE 

APPLE COMPUTERS 

Super Space Wars $ 9.95 

States & Capitals 9.95 

Moving Point 

Average 19.95 

Stock Options ., 24.95 

Finance 12.95 

Bonds 12.95 

COMMODORE PET 

Stock Options 24.95 

Finance 12.95 

Bonds 12.95 



Stock Analyzer 22.95 

Mortgage 14.95 

Space Intruders 
("Best Game of 1979") ..$19.95 

Jury/Hostage 9.95 

Kentucky Derby/Roulette 9.95 

Alien I.Q./Tank 9.95 

Tunnelvision/Maze Chase 14.95 

Submarine Attack 9.95 

Battle of Midway 7.95 

Laser Tank Battle 9.95 

Swarm 14.95 

Baseball 9.95 

Super Startrek 14.95 

PET Music Box 29.95 



puters, Centronics printers, 


available a low-cost con- 


ting closer and closer to 


print at 120 cps, with proof 


Hewlett-Packard 


troller which interfaces the 


reality .... CompuServe , the 


copies at over 200 cps. 


calculators, and ADT secu- 


5!4-inch hard-disk drive 


company that provides the 




rity systems. Xerox plans to 


and floppy-disk drives to 


MicroNet information util- 


1 oo Good To Be True? A 


open at least 200 such 


several personal-computer 


ity, has been negotiating 


outlets in at least 50 cities 


systems. These products 


with H & R Block about a 


rumor recently heard at 


within 2 years. 


should become available in 


corporate merger, with in- 


BYTE says that a major 




1981. 


tent to become a subsidiary 


manufacturer will shortly 


AApple Foundation 




of the income-tax firm. 


introduce a 5-inch floppy- 


Jtlandom News Bits: 




disk drive with a tenfold in- 


Awards Grants To 


JTLandom Rumors: A 


crease in density. This 


Schools: The Apple Educa- 


Votrax (Division of Federal 


sounds too good to be true. 


tion Foundation, chartered 


Screw Works, 500 Stephen- 


semiconductor manufac- 


Will standard media sup- 


by Apple Computer Inc, 


son Hwy, Troy MI 48084) 


turer will soon introduce 


port such an 


has awarded $120,000 


has announced a new voice 


two integrated circuits that 


extension?... CH 


worth of equipment to 


synthesizer with an 


together will handle all in- 




schools and individuals to 


unlimited vocabulary in 


terfacing requirements for 


X'iicrominis and 


expand the use of 


seven languages and con- 


the S-100 bus, thereby 


microcomputers in educa- 


trollable inflection. The 


reducing the number of 


Micromaxis: Two new 


tion. The foundation plans 


Model VSB, built on a 


components required by 


words have been coined to 


to donate another $250,000 


single printed-circuit card, 


S-100 master and slave 


describe the newer micro- 


worth of equipment to sup- 


is intended to interface with 


boards. The two devices 


processors. If an 8-bit pro- 


port programs at all educa- 


terminals, electronic type- 


will provide all the 


cessor is called a "micro," 


tional levels. Current reci- 


writers, word processors, 


necessary bus buffering, 


then a 16-bit 


pients include Iowa State 


and other equipment. The 


control signals, and 


microprocessor must be a 


University; Bowditch 


unit is controlled by 8-bit 


address decoding and will 


"micromini." That is the 


Middle School in Foster 


input commands that select 


meet IEEE S-100 specifica- 


conclusion of many in the 


City, California; North 


phonemes and inflection. 


tions.. . .Hewlett-Packard 


industry, particularly since 


Texas State University; 


Original equipment 


(HP) is rumored to be 


many of these new 16-bit 


Educational Services 


manufacturer price is 


working on a hand-held 


microminis will be com- 


Management Corporation 


$280.... A national FORTH 


calculator that is program- 


peting head-on with ap- 


in Raleigh, North Carolina; 


language group is in 


mable in BASIC (maybe 


plications that were 


Children's Hospital in 


operation. They publish a 


they should call it a com- 


previously the exclusive do- 


Philadelphia; the National 


newsletter, distribute soft- 


puter). Rumor is that they, 


main of the 16-bit minicom- 


Science Foundation; Dr 


ware, and conduct 


and several others, will in- 


puters. 


Robert N Noyce, vice presi- 


meetings. For information 


troduce such units by year 


It therefore follows that 


dent of Intel Corporation; 


contact: Jim Flounoy, 17370 


end. A few have already 


the 32-bit microprocessors, 


and others. 


Hawkins Ln, Morgan Hill 


been introduced in 


which are expected within 


Other participating con- 


CA 95037.... Radio Shack 


Japan Texas Instruments 


three years, should be call- 


tributors include the Bell & 


has released a software 


(TI), which has been work- 


ed "micromaxis," since 


Howell Company, 


package for its TRS-80 


ing on a disk-drive system 


they will most likely com- 


Heuristics Inc, and Integral 


Model I which enables 


of its own, is now 


pete for applications 


Data Systems Inc. 


users to originate Mailgram 


negotiating with a number 


previously handled by 


For more information, 


messages. Users must have 


of outside suppliers for 


large mainframe com- 


contact the Apple Educa- 


a Western Union (WU) 


8-inch Winchester-type 


puters. At least that is what 


tion Foundation, 20605 


Electronic Mail account, 


hard-disk drives to be in- 


many industry watchers 


Lazaneo Dr, Cupertino CA 


and if so, users are billed 


cluded in a new small- 


think. 


95014. 


monthly by WU for 


business/word-processor 


Well now... my question 




messages sent.... Matsushita 


system to be introduced 


is: what do we call a 4-bit 


0%-Inch Mini- 


Electric, Osaka, Japan, has 


next year. TI, however, is 


microprocessor? Is it a 


introduced a single- 


still pursuing in-house 


"minimicro"? 


Winchester Disk Introduc- 


component voice syn- 


designs. TI is also 




ed: Shugart Technology of 


thesizer that generates 


negotiating with several 


MAIL: I receive a large 


Scotts Valley, California 


either 10 seconds of high- 


tape-drive suppliers for a 


number of letters each 


(not to be confused with 


quality speech or up to 30 


backup storage 


month as a result of this 


Shugart Associates) has in- 


seconds of low-quality 


system The rumor is that 


column. If you wish a 


troduced a 5 Va -inch 


speech. The integrated cir- 


Tandon Magnetics, 


response, please include a 


Winchester-type hard-disk 


cuit uses only 28 pins and 


Chatsworth, California, is 


stamped, self-addressed 


drive with a 6.38-megabyte 


operates from +5 V. The 


about to announce a 


envelope. 


unformatted capacity. It is 


device will probably be 


2-megabyte quad-density 




the same size and uses the 


used in consumer ap- 


5-inch floppy-disk drive 


Sol Libes 


same power-supply 


pliances, cars, etc Na- 


with a $375 original eguip- 


Amateur Computer 


voltages as a standard 


tional Semiconductor, San- 


ment manufacturer price 


Group of New Jersey 


5!4-inch floppy-disk drive. 


ta Clara, California, has in- 


tag Look for Integral 


(ACG-NI) 


[See Tom Manuel's article, 


troduced a microprocessor 


Data Systems to introduce a 


1776 Raritan Rd 


"The Hard Disk Explosion, " 


that includes a read-only- 


$1500 letter-quality dot- 


Scotch Plains NJ 07076 


on page 58 of this issue for 


memory-resident BASIC in- 


matrix printer. It will use 




more cfefaz/s.... CM] 


terpreter and 64 bytes of 


overlapping dot-matrix 




Lobo Drives, Goleta, 


user memory. The single- 


printing. To be called 




California, plans to make 


chip computer keeps get- 


"Paper Tiger Plus," it will 





Circle 62 on inquiry card. 




IT U i .W. i 



NOBODY DOES IT BETTER. 



In 1 975. Microsoft wrote the first BASIC 
interpreter for the 8080. Today, hundreds 
of thousands of microcomputers run with 
Microsoft software. And tomorrow— a full 
line of system software for the 8086 and 
Z8000. With microcomputer software, 
nobody does it better. 

BASIC Compiler Microsoft's BASIC 
compiler is the ideal software tool for the 
development of BASIC applications pro- 
grams for resale. Compiled object code for 
any application may be distributed to your 
customers on diskette or ROM, thus safe- 
guarding the source program. And execu- 
tion speeds with our compiled BASIC code 
are faster than with any other BASIC. Highly 
optimized, compact object code means 
maximum efficiency in any application. 
The BASIC Compiler supports all the lan- 
guage features of our BASIC-80 Interpreter. 
Comes with macro assembler and loader. 
RunswithCP/M, ISIS-ll.TRSDOS. $395. 

BASIC Interpreters for 8080, 
Z80, 8086, 6800, 6809 Language 
features above and beyond any other BASIC 
have made Microsoft's BASIC the world's 
most popular interpreter. And now three new 
versions are available for the 8086, 6800, and 
6809. The latest releases of BASIC-80 and 
BASIC-86 support the new WHILE condi- 
tional, plus CHAINing of programs with 
COMMON variables, dynamic string space 
allocation and variable length records in ran- 
dom files. All versions have double precision 
arithmetic, full PRINT USING, tracing, 
renumbering, edit mode, and many other 
features. BASIC-80 for CP/M, ISIS-II. 
TEKDOS: S350. BASIC-86 standalone 
on SBC 86/12: $600. BASIC-68 for FLEX: 
$200. BASIC-69 for FLEX: $250. 

CO BO L-80 Compiler The best im- 
plementation of the world's most widely used 
programming language is COBOL-80 from 
Microsoft. As small business applications be- 
come not-so-small, COBOL-80 is ready with 
powerful use of disk files, data manipulation 
facilities. CHAIN, segmentation and inter- 
active ACCEPT/DISPLAY Plus three- 
dimensional arrays, full COPY facility, 
indexed and relative files and an optional 
packed decimal format that saves on mass 
storage by as much as 40%. Comes with 
macro assembler and loader. Runs on 
CP/M, ISIS-II, and TRSDOS. $750. 



NEW! muSIMP/muMATH 79 

At last, a sophisticated math package for 
microcomputers. muMATH performs mathe- 
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precision integer arithmetic and symbolic 
matrix inversion. muMATH is an invaluable 
tool for engineering and scientific applica- 
tions involving lengthy, analytical computa- 
tions. It is also an ingenious teaching method 
for all levels of math from arithmetic to 
calculus. muMATH is implemented in mu- 
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complex symbolic manipulations. muSIMP/ 
muMATH Package, CP/M versions: $250. 

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cost version for microcomputers, Features 
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sources; program control structures such 
as an extended COND and a multiple exit 
LOOP; user functions defined as CALL by 
Value or CALL by Name; and 83 LISP func- 
tions. muLISP-79, CP/M version: $200. 

NEW! XMACRO-86 For the 

development of 8086 programs, our new 
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or TEKDOS system. $300. 

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are developing applications software in- 
house or bundling hardware and software for 
resale, a database manager could be the 
software tool you've been looking for. Micro- 
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CP/M; and Microsoft's FORTRAN-80 has 
been implemented as the host language. 
When an application becomes limited by trad- 
itional floppy disk file handling, but remains 
overpowered by the cost and mainte- 
nance of a minicomputer, the solution is 
Micro-SEED. $900. 

FORTRAN-80 Compiler Micro- 
soft FORTRAN-80 is the most complete 
microcomputer FORTRAN available. It 
has all of ANSI-66 FORTRAN (except 
COMPLEX data), plus unique enhancements 
for use in the microcomputer environment. 
An extensive library of single and double 



precision scientific functions, too. Comes 
with macro assembler and loader. Versions 
for CP/M, ISIS-II, TEKDOS. $500. 

M ACRO-80 Assembler The most 
powerful microcomputer assembler on the 
market today is Microsoft's MACRO-80. It is 
fast, and it supports Intel-standard macros, 
relocation pseudo-ops, conditionals and list- 
ing controls. MACRO-80 comes with a relo- 
catable linking loader and runs with CP/M, 
ISIS-II, and TEKDOS. $200. 

EDIT-80 Text Editor Random 
access to floppy disk files makes EDIT-80 the 
fastest microcomputer text editor. It's the 
essential tool for creating and maintaining all 
files. EDIT-80 includes FILCOM, a file com- 
pare utility. EDIT-80, CP/M version: $120. 

Prices quoted are USA domestic only. 
OEMs should contact Microsoft for prices. 



N. os 

MICROSOFT\ 


5 

O- 
O 


a 
co 

CO 


CO 

O 
Q 
CO 
CC 

I- 


CO 

O 

CO El 

PS 


CO 

O 
Q 

111 

F 


BASIC-80 
INTERPRETER 












BASIC 
COMPILER 




• 


□ 


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FORTRAN-80 
COMPILER 




• 


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■ 


• 


COBOL-80 
COMPILER 




• 




• 




muMATH/muSIMP 
muLISP 






□ 






MICROSEED 
DBMS 












EDIT-80 
TEXT EDITOR 






□ 


■ 




MACRO-80 
ASSEMBLER 




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□contact Microsoft Consumer Products 



10800 NE 8th, Suite 819 
Bellevue.WA 98004 
206-455-8080 Telex 328945 




We set the standard. 









This selected list of FORTH vendors is meant to be an overview only. For complete details contact the vendors. Many of the products, listed 
as fig-FORTH versions, are implementations of the FORTH Interest Croup software customized for a given machine and available in machine- 
readable (as opposed to printed) form. 

When purchasing a version of FORTH, check to see what source the version is based upon. AH good versions of FORTH are based on either 
the FORTH Inc or the FORTH Interest Croup versions. Some existing implementations use nonstandard shortcuts that limit the usability of the 
product; these should be avoided. 

Literature on FORTH is scarce, so be prepared to puzzle through cryptic documentation. Miller Microcomputer Services offers a wide selec- 
tion of books on FORTH (the only selection we know of). Particularly suitable are microFORTH Primer (supplied with the purchase of 
MMSFORTH) and Using FORTH, both written by FORTH Inc. 

STOIC is a FORTH-like language available from the CP/M Users' Group and is listed because of its low price. N/A refers to information 
unavailable at the time this table was compiled.... GW and CHF 



Selected FORTH Vendors 



Manufacturer 



Product Name(s) 



Machine Requirements 



Format 



Cost 



Notes 



Acropolis Software 
17453 Via Valencia 
San Lorenzo CA 94580 
14151 2766050 



AFORTH (based on 
fig-FORTH) 



Any machine running Micropolis disks 
and MDOS operating system 



Floppy disk 



5150 



Includes 8085 assembler, double 
precision fixed-point math, enhanced 
disk access, other features. 



Cap'n Software 
P0B 575 

San Franciso CA 94101 
14151 540-0202 



fig-FORTH 



Apple II with disk 



5 inch floppy disk $140 



FORTH hot line available for ques 
tions. Extra packages (Apple high 
resolution graphics, floating point) 
available at extra cost. 



CP/M Users Group 
1651 Third Ave 
New York NY 1D028 



STOIC [not FORTH, 
but a FORTH 
variant) 



Any CP/M machine. 



8-inch floppy disk $20 



See editorial lor further details. 



FORTH Inc 

2309 Pacific Coast Hwy 
Hcrmosa Beach CA 90254 
(213I 372-8493 



FORTH, polyFORTH, 

microFORTH, 

picoFORTH 



Versions for various machines: 8080, 
8086, 6800, 1802, LSI-11; also 
handles versions for' minicomputers 
and mainframes 



Varies with machine. $2500 up 
($495 for 
picoFORTHI 



These are the inventors of the 
language; they supply custom 
packages and extensive support; 
picoFORTH (for 8080 or 1802] can 
be directly upgraded to polyFORTH. 



FORTH Interest Group 

POB 1105 

San Carlos CA 94070 



i-FORTH 



Various machines with 16 K bytes or 
more: 8080, 6502, 6800, LSI-11, 
9900, PACE; disk preferable 



Printed listings; must be $20 
customized by user. 



$20 includes installation manual and 
assembly language source for one pro 
cessor (8080, etc); requires some 
work by user to install; quality pro- 
duct at a low price. 



FORTH Power 
17390 Hawkins Ln 
Morgan Hill CA 95037 
(415) 471 1762 



j FORTH 



Heath WH-89 or 6800 EXORciser 



NIA 



N/A 



Forthright Enterprises 
POB 50911 
Palo Alto CA 94303 
(415) 856-0450 



fig-FORTH 



CP/M machine, 16 K bytes 



8-inch CP/M floppy disk $30 



Includes all source code. 



John James 
POB 348 

Berkeley CA 94701 
(415) 526-8815 



fig-FORTH 



PDP-1 1, all models; stand alone or 
running under RT-1 1 or RSX-1 1M; 
24 K bytes or more 



■inch floppy disk 



$140 



Package includes all documentation 
and source code; also offers a book 
ol FORTH reprints. 



M&B Design 
820 Sweetbay Dr 
Sunnyvale CA 94086 
(408) 243 0834 



polyFORTH CP/M 



8080 CP/M system 



8-inch CP/M floppy 
disk 



$4000 



Multitasking version of FORTH run- 
ning on CP/M system with 32 K 
bytes or more; includes utility pro 
grams and interface to CP/M; system 
uses CP/M 1/0 drivers only. 



Miller Microcomputer Services 
61 Lake Shore Rd 
Natick MA 01760 



MMSFORTH (based on TRS-80 Model I, with Level II BASIC, Cassette or 5-inch $59.95, cassette 

FORTH Inc micro- 16 K bytes or more floppy disk $79.95, disk 

FORTH) 



Offers support of product, consulta 
tion, newsletter, additional FORTH 
products, and a wide selection of 
FORTH books. 



The Stackworks 
321 E Kirkwood Ave 
Bloomington IN 47401 
(812) 336 1600 



SL5 (FORTH 
under a dif 
ferent name) 



Any CP/M machine, 8080 or Z80 



8-inch CP/M floppy disk $150 (noncommercial 
use), $1500 
(commercial use) 



This language is essentially an im- 
plementation of the 1977 FORTH 
Standard: SL5 includes a debug 
package and packages that allow the 
generation of condensed, stand-alone 
programs as either CP/M, .COM files, 
or as programs to be placed in read 
only memory. 



Talbot Microsystems 
7209 Stella Link 
Suite 112 
Houston TX 77025 
(7131 666-7588 



fig-FORTH 



Minimum 12 K bytes (20 K better 

for FLEX 9.0) 

6609 SwTPC FLEX 9.0 



5-inch floppy disk 
soft sectored 



$39.95 



Offers telephone support of product. 







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adjustable tractor feed 3"-16"; user adjustable 
platen; programmable tabs, forms length and 
line spacing; out of paper signal; self-test; 
interface options — RS-232C, Centronics 
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with prices, terms and delivery to meet your needs too. 



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a subsidiary of DBtametrtCH Corporation 



Circle 63 on inquiry card. 



BYTE August 1980 99 



What Is FORTH? 
A Tutorial Introduction 



John S James 

POB 348 

Berkeley CA 94701 



FORTH is a programming 
language with a small but fast- 
growing and enthusiastic user com- 
munity. Though easy to learn at a ter- 
minal, it is difficult to explain 
abstractly because it is so different 
from other languages. Even 
advocates do not agree why it is good 
or how it should be used. 

FORTH was developed for control 
applications (using a computer to run 
other machinery), data bases, and 
general business. It is least useful for 
big number-crunching jobs (eg: 
writing a matrix inversion routine), 
although it can link to subroutine 
packages written in other languages 
to incorporate such functions. Unlike 
Pascal, FORTH gives the user com- 
plete access to the machine and does 
not try to guard the programmer 
against mistakes. But its modularity 
and other forms of error control 
allow production of remarkably bug- 
free application programs — perhaps 



Acknowledgments and Availability 

Listings 1 thru 7 were run on a FORTH 
system for the Apple II provided by Cap'n 
Software, POB 575, San Francisco CA 94101. 
The PDP-11 examples were run on a system 
written and distributed by the author. The 
8080 example was provided by John Cassady 
of the Forth Interest Group, POB 1105, San 
Carlos CA 94070; a similar 8080 FORTH 
system is available from Forthright Enterprises, 
POB 50911, Palo Alto CA 94303. Other 
members of the Forth Interest Croup con- 
tributed helpful suggestions. And of course we 
are indebted to the inventor of FORTH, 
Charles Moore of FORTH Inc, 2309 Pacific 
Coast Hwy, Hermosa Beach CA 90254, who 
started it all. 



more than any other language in 
common use. The compiler uses 
much less memory than Pascal does, 
and its programs run about equally 
fast. FORTH is much more interac- 
tive than most conventional 
implementations of Pascal. FORTH is 
available on most common personal 
computers (eg: Apple, TRS-80) and 
all major microprocessors (eg: 8080, 
6800, 6809, 6502, PACE, LSI-11, and 
9900). An international FORTH Stan- 
dards Team exists, and standard 
systems are virtually identical among 
all different machines. 

This article will describe what it is 
like to program in FORTH. A group 
of annotated terminal sessions, 
shown in listings 1 thru 10, will pro- 
vide more details on the language 
itself. 

The Philosophy of FORTH 

FORTH reduces the cost of a 
subroutine to very little, and the 
whole language is built on functions 
that are like subroutine calls. The 
programmer keeps defining new 
words (new functions) from old ones 
until, finally, one of them is the 
whole job. Most programmers keep 
each definition short, usually one to 
three lines not counting comments. 
The definitions are compiled as 
entered and are immediately ready to 
run. 

Because FORTH definitions are 
short, all possible execution paths of 
the definition can be tested easily. 
Since most functions work exactly the 
same when executed as commands 
from the terminal or when used as 
components in further definitions, 



they can be tested immediately from 
the terminal. And the functions are so 
general that there is no sharp distinc- 
tion between program and data. 

Since programmers define their 
own operations, special application 
libraries of FORTH words can be 
developed. The new routines are 
integrally part of the language, so 
they do not need any special calling 
sequences, and they are immediately 
ready to run. Even the original words 
supplied with the system (there are 
about one hundred of them), can be 
redefined if desired, adapting the 
language for special circumstances. 
Also, programmers can create their 
own data types or operation types 
(eg: their own kinds of arrays or 
other data structures, or new classes 
of operations). This flexibility allows 
unprecedented "customization" of a 
language to the requirements of a par- 
ticular installation or application. 
The finished programs are easily 
modifiable when requirements 
change because they are composed of 
pretested building blocks specially 
designed for that kind of program. 



Stack and Postfix Notation 

A smaller convenience of FORTH 
is that you do not have to do much 
coding when you start a new pro- 
gram. As soon as the system comes 
up, all your previous work is ready to 
go, just as if it were originally part of 
the language. 

A feature that some people do not 
like is FORTH's use of a stack 
(explained below) and its postfix 
notation (also called reverse Polish 



100 August 1980 © BYTE Publications Inc 




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Deselect around PROMs. Our 

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Our features make the board 
easily used and expanded. You 
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Standard S-100 Interface. Our 
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also. 

Central Data Corporation, 713 
Edgebrook Drive, PO Box 2530, 
Station A, Champaign, IL 61820. 
(217) 359-8010 

Central Data 

BYTE August 1980 101 



Most FORTH operations 
communicate only 
through a stack. 



STACK 



OPERATION 

JUST 

PERFORMED 













7 












5 




6 


6 


13 








4 


4 


9 


9 


9 


9 


117 


117 


- 


- 


- 


- 


- 


- 


- 


- 


- 


(BEGIN) 


4 


5 


+ 


6 


7 


+ 


* 


(END) 



notation or RPN). In postfix notation 
(a system used on most Hewlett- 
Packard calculators), arithmetic for- 
mulas are written with the operations 
after their arguments, not between 
them. For example, "2 + 3" becomes 
{23+} in FORTH or other 
postfix systems; "(4 + 5)*(6 + 7)" 
becomes {45 + 67+*}. (See 
explanation below.) No parentheses 
are needed in postfix. 

Some programmers do not like 
postfix, and they ask, "Why doesn't 
someone write an algebraic-to-postfix 
translator for FORTH? That would 
be easy to do." The reason is that 
postfix has benefits far more impor- 
tant than the compiler-writer's conve- 
nience. It greatly simplifies linkage to 
subroutines. With postfix, you do not 
need any CALL statement or argu- 
ment list, or any formal parameters in 
the subroutine. While arithmetic- 
formula operations (add, subtract, 
etc) must take either one or two 
arguments and return exactly one 
result, postfix functions can have any 
number of arguments or results. 

In FORTH, most operations com- 
municate only through a stack. The 
stack, perhaps the most important 
data structure in programming, is 
used in almost all languages, but most 
languages hide it from the user. In 
FORTH, the user controls the stack 
directly. 

A stack is a pile of numbers where 
the last ones put in are the first ones 
taken out; that is, you can only 
remove the number that is on top of 
the stack. It is like a stack of trays in a 
restaurant; trays are conveniently 
added and removed only at the top. 
(Unfortunately, computer-science 
texts do not agree on terminology, 
and a few call the top of the stack "the 
bottom.") 

To see how a stack works in com- 
putation, consider the expression 
{23+} above. In FORTH, 
numbers are compiled as operations 
which place their values onto the 
stack. So when the 2 is executed, 
it is placed on top of the stack, which 
then looks as follows: 



Figure Is Evaluation of the postfix-notation expression, {45 + 67+ *}. 
Numbers are pushed onto the stack at the top. Operators (here, + and *) pop the top 
two entries off the stack and push the result of that operation back on the stack. For ex- 
ample, the first plus sign (column 4) replaces the 4 and 5 on the stack with 9, the result 
of the addition operation. 



compiler's code may do number- 
crunching several times faster still. 



where the dashes represent whatever 
data may have been on the stack 
before. Then after the 3 has been en- 
countered, the stack becomes: 

3 

2 



Then the + is executed. The 
1-character word + takes two 
arguments from the stack (destroying 
them), performs the addition, and 
leaves the result on the stack. So the 
stack finally is: 



The reader can verify that when the 
formula {45 + 67+*} is 
executed, the stack goes through the 
sequence shown in figure 1. 

Now we can see why FORTH is not 
the best language for big number- 
crunching jobs. Numbers to be 
operated on must be moved to the 
stack in addition to whatever opera- 
tions are to be carried out, and this 
extra movement slows FORTH down 
for this kind of computation. Once 
on the stack, however, arithmetic is 
fast (for example, single instruction 
execution for addition on some 16-bit 
machines, more for 8-bit machines). 
Also, FORTH can link the useful in- 
structions of one routine and those of 
another in as little as one or two in- 
struction executions (depending on 
machine architecture). This makes 
FORTH programs much faster than 
BASIC, usually ten times faster or 
more (assuming an interactive 
BASIC, that is— FORTH is always in- 
teractive). But a good FORTRAN 



Characteristics of FORTH Code 

FORTH is a structured language (as 
is Pascal) in that it has no GOTO or 
statement labels in the language. 
Discussion of structured program- 
ming is outside the scope of this arti- 
cle, but its importance for program 
correctness and maintainability is 
recognized. 

FORTH object code (ie: a compiled 
program) is extremely compact, even 
more so than machine language. The 
reason is that no matter how much 
work an operation performs, each 
invocation of it takes the same space 
in the object program — two bytes. 
The bigger the program, the greater 
the memory advantage, since the 
hierarchical structure of programs 
allows increasingly powerful and 
application-targeted operations to be 
built up. But FORTH has a relatively 
large run-time memory overhead, so 
small programs can take less total 
space in other languages. 

{The reason that a FORTH call can 
be shorter than a normal machine- 
language subroutine call (usually 
three bytes) is that a FORTH program 
is interpreted by a FORTH interpreter 
(also part of the FORTH language) in 
much the same way that a BASIC 
program is interpreted by a BASIC 
interpreter. The "relatively large run- 
time memory overhead" mentioned 
above is the FORTH interpreter plus 
a core of FORTH words defined in 
machine language. When a FORTH 
program is very large, it saves enough 
memory in FORTH calls to make up 

for run-time memory overhead 

GWj 

The complete FORTH system 
(itself largely written in FORTH) 
takes about 7 K bytes, and this whole 
system including the compiler is com- 



102 August 1980 © BYTE Publications Inc 



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monly left in memory as a run-time 
package. Therefore, 16 K bytes and a 
floppy disk for storing source pro- 
grams are sufficient hardware for an 
excellent FORTH system (compare 
this with the memory requirements of 
Pascal, 48 K bytes or more). When 
compactness is especially important, 
as when programs are burned into 
read-only memory and embedded in 
machinery, FORTH's compiler, ter- 
minal handler, and operation 
names — anything not needed to 
run — can be stripped out of the 
application program, leaving a run- 
time package of about 800 bytes, 



instead of the usual 7 K bytes. 

FORTH programming is reentrant; 
this means that different users can 
share the same copy of a program in 
memory while running at the same 
time. FORTH easily handles 
multitasking, including multiple ter- 
minals used for program develop- 
ment. (At present, however, most of 
the low-cost systems on the market 
are still single-user.) FORTH is recur- 
sive, meaning that routines can 
invoke themselves. 

Suppose you want to link your 
high-level-language program to a 
machine-language subroutine (eg: 











iAdn 


LAIAbC 










B""*' 


L W J 


*«S? 


m 






THE 


UADI 




IrAKI 


ititiMUi 


We know you hardcore bit hack- 


• It replaces subroutines by 




ers will recognize the computing 


individual words and related 




power derived from combining the 


groups of words called 




FORTH language with the 6809, 


Vocabularies. These are quickly 




today's most advanced 8 bit 


modified and tested by editing 




microprocessor. 


1024-character text blocks, called 




And we know you'll understand 


screens, using built-in editor. 




this machine's 16 bit math, indirect 






addressing and two stacks are 


tFORTH is a basic system imple- 




ideally suited for implementing 


mented for SS-50 buss 6809 systems 




FORTH. 


with the TSC FLEX 90 disk oper- 




But. ..should anyone need further 


ating system. It is available on 5 1 /4" 




convincing that FORTH provides a 


or 8" single density soft-sectored 




new dimension in power, speed 


floppy disks. $100.00 




and ease of operation, consider 






the following: 


tFORTH + consists of tFORTH plus a 




• It's a modern, modular, structured- 


complement of the following 




programming high-level com- 


FORTH source code vocabularies: 




piled language. 


full assembler, cursor controlled 




• It's a combined interpreter, 


screen editor, case statements, 




compiler, and operating system, 


extended data types, general I/O 




• It permits assembler code level 


drivers. $250.00 




control of machine, runs near 






speed of assembler code, and 


firmFORTH is an applications pack- 




uses less memory space than 


age for use with tFORTH. It provides 




assembler code. 


for recompilation of the tFORTH 




• It increases programmer produc- 


nucleus, deletion of superfluous 




tivity and reduces memory hard- 


code and production of fully 
rommable code. $350.00 




ware requirements. 




( 


Sail or write today. 








KENYONl 




3350 Walnut Bend, Houston, Texas 77042 • (713)978-6933 







you may be controlling a high-speed 
device and need the full speed of the 
computer to keep up). Many 
languages make this linkage difficult 
or impossible. In FORTH, however, 
it is very convenient. You can type in 
or load from disk a machine-language 
routine, using a FORTH assembler, 
and the new routine can be executed 
immediately. Listing 9 shows 
examples for PDP-11 and for 8080. 

The word CODE invokes the 
FORTH assembler and begins the 
definition of a machine-language 
routine. Mnemonic instructions and 
address-mode symbols are 
understood by this assembler, and the 
whole power of FORTH is available 
for address arithmetic at assembly 
time. FORTH assemblers use postfix 
notation, so op codes come after their 
addresses, not before as in conven- 
tional assemblers. 

The machine-language code is 
generated as the definition is being 
entered. The completed operation 
works just like any other FORTH 
word, so the user does not need to use 
any special calling sequence, or even 
need to know which operations are 
defined in code and which are not. (In 
fact, about fifty FORTH words are 
written in machine language — all 
other words in FORTH are ultimately 
defined in terms of these fifty words.) 

The FORTH assembler allows 
structured conditionals and loops at 
the machine-code level; it can also 
assemble unstructured code if 
desired. Users can define their own 
macro-instructions, use custom-made 
data types, etc. 

In other words, the FORTH 
assembler allows structured program- 
ming even in machine code, and it 
links the resulting machine-language 
subroutines into the system 
immediately. No separate assembly 
and linking-loader passes are needed, 
and the associated file management 
overhead is avoided. 

Some More Advantages 

FORTH programs are highly 
transportable between different com- 
puters. Any assembly-language 
routines used by the program must be 
rewritten, but most applications do 
not need any assembly, and very few 
need more than a handful of short, 
critical routines. When FORTH 
systems have been designed for com- 
patibility, large applications can be 
moved among very different 



104 August 1980 © BYTE Publications Inc 



Circle 66 on inquiry card. 



INDUSTRY 

LEADER 

ANNOUNCES 

MERGER. 



MicroPro proudly announces MailMerge 
capabilities along with WordStar 2.0 



Now you have another terrific reason to 
purchase WordStar, the industry's leader in 
microcomputer word processing. And that 
reason is called MailMerge. A new option 
that allows you to churn out letter quality 
form letters with full substitution capabilities, 
as well as chained and multiple copy printing. 

And lots more. 

Plus WordStar 2. also offers other 
new and powerful features. Like hyphen 



help, decimal tab, paragraph indent, and 
copy/rename/run-another-program. 

No wonder that in less than a year, more 
than 7500 people have purchased WordStar 
from over 350 dealers around the world. 

So go ahead. Call (415) 457-8990 for a 
dealer nearest you. And just think, WordStar 
was a very popular software package before 
MailMerge. 

Imagine how incredibly popular it will 
be now. 




iiff©Prot 



INTERNATIONAL CORPORATION 

Leads the way. 

MicroPro International Corporation 1299 4th Street, San Rafael, California 94901 Telex 340388 

Dealer/Distributor/O.E.M. inquiries invited. 



Prices and specifications subject to change without notice. 



BYTE August 1980 105 



machines, with little or no change. 
For example, it can be practical to 
down-load program development 
from a PDP-11 to a TRS-80 or an 
Apple II. It is even possible to write 
the software for a product before a 
hardware commitment is final. 

Another advantage is that FORTH 
is a self-contained operating system. 
The 7 K bytes include terminal and 
disk handlers and a rudimentary file 
system. No other software is needed 
anywhere in the computer. Yet, if a 
monitor in read-only memory is 
available, FORTH can use it; and 
FORTH can run as a task under some 
other operating system (eg: CP/M) 
when that is wanted. FORTH can link 
together otherwise incompatible 
pieces of systems: software in read- 
only memory, operating systems, 
subroutine packages, and hardware. 
It provides a user interface that 
enables subroutine packages normal- 
ly used by batch (ie: noninteractive) 
programs, mostly on older, larger 
computers, to be used interactively. 

FORTH puts you in charge of your 
computer. You can understand 
everything happening in your soft- 



ware or in any desired parts of it, and 
you can change it. This means no 
more "black box" systems that only 
the manufacturer's specialists can 
understand, no more dependence on 
someone else for upgrades, fixes, or 
documentation, and no more ques- 
tion of who is responsible if software 
does not work. The whole system is 
written in FORTH, right down to the 
bits — your application programs, the 
compiler, the operating system, the 
I/O drivers, etc. You do not have to 
learn some other language or be a 
systems specialist to modify it. 

Disadvantages 

Few FORTH systems used today 
have floating-point arithmetic. This is 
not a fault of the language; rather, it 
reflects its history in microcomputer 
control applications, where integer 
arithmetic is often needed for speed. 
Now there is more pressure for 
floating point, and it is becoming 
available. 

A more fundamental limitation of 
FORTH is that it is not a typed 
language (unlike Pascal). For exam- 
ple, if an integer operation is per- 




RCA VP-600 series ASCII keyboards are available in two formats. 
You can choose either a 58-key typewriter format. Or a 74-key version 
which includes an additional 1 6-key calculator-type keypad. Both can 
be ordered with parallel or serial output. 

These keyboards feature modern flexible membrane key 
switches with contact life rated at greater than 5 million operations. Plus 
two key rollover circuitry. A finger positioning overlay combined with light 
positive activation key pressure gives good operator "feel," and an on- 
board tone generator gives aural key press feedback. 

The unitized keyboard surface is spillproof and dustproof. This plus 
high noise immunity CMOS circuitry makes these boards particularly 
suited for use in hostile environments. 

Parallel output keyboards have 7-bit buffered, TTL compatible 
output. Serial output keyboards have RS 232C compatible, 20 mA 
current loop and TTL compatible asynchronous outputs with 6 
selectable baud rates. All operate from 5 V DC, excluding 
implementation of RS 232C. 

For more information contact RCA Customer 
Service, New Holland Avenue, Lancaster, PA 1 7604. 
Or call our toll-free number: 800-233-0094. 



'Oplional user price lor VP-60 1 Dealer and OEM 



RC/1 



pricing available 



formed on a floating-point quantity, 
no message is printed either at com- 
pile time or at run time to warn of this 
error. (However, the user can add 
type checking and other error- 
preventing operations into any 
FORTH word.) 

It may seem that unreliable code 
would result from the untyped nature 
of FORTH, but, in fact, FORTH code 
is remarkably solid and bug-free. The 
modularity and excellent testing 
environment aid error control; and 
type mismatches are less dangerous 
than most other mistakes because 
they are easy to detect. 

Another criticism of FORTH is its 
lack of a directory file structure. 
Again, this is historical and is not a 
characteristic of the language, which 
can be developed to use any kind of 
files. 

The traditional FORTH file system 
is primitive, but in practice it has 
worked very well. The entire disk (or 
disks) is a single virtual array of 
blocks numbered from 1, with the 
block size standardized at 1024 bytes 
regardless of physical disk sector size. 
The blocks (called screens because 
they can be displayed as sixteen 
64-character lines on a terminal) are 
automatically buffered so that they 
are physically read and written only 
when necessary. A LOAD command 
will read a given screen and treat the 
information exactly as if it had been 
typed in a terminal session, thereby 
compiling source code or executing 
commands (depending on the con- 
tents of the screen). The LOAD 
instruction can be executed within a 
screen; in this way, a single LOAD 
command can control the compila- 
tion of large source programs. 

This disk-based file system allows 
any part of the disk to be read or 
written with a single access. Load 
screens or data areas can be saved by 
name, and portions of the disk can be 
protected by redefining the names of 
a few input and output operations so 
that they check before writing and/or 
reading. 

The disadvantage of this system is 
that there is no directory; when a new 
disk is inserted, the user or the pro- 
gram must know the block numbers 
for load screens and data files. Also, 
FORTH source programs are tradi- 
tionally stored without tabs or trun- 
cation of blank lines, making white- 
space (ie: unused area on a line) and 



106 August 1980 © BYTE Publications Inc 



Circle 68 on inquiry card. 




MicroNET is just the tip of the iceberg 



We've been telling you that MicroNET 
CompuServe's personal computing service, 
is the best thing that's happened to per- 
sonal computers since electricity. It still is, 
but now there's more. A lot more. 

Welcome to CompuServe's information 
service. 

• News. Weather. Sports. Major regional 
newspapers. Plus international news 
services. 

• Finance. MicroQuote. Updates and 
historical information on stocks, bonds and 
commodities. 

• Entertainment. Theatre, book, movie and 
restaurant reviews. Plus opera, symphony, 
ballet, dance, museums, galleries. . . 

• Electronic Mail. Create, edit, send and 
receive messages from any other Compu- 
Serve user. . . nationwide. 

• Home & Educational Reference Service. 
Anything you want to know. . . from ency- 
clopedia information to household tips. 

• CompuServe user information. In case 
you need technical help... and information 
on new services as they become available. 



• MicroNET. All we've offered before and 
added lately with more to come. This in- 
cludes Software Exchange.line printer art 
gallery, challenging games, programming 
languages, word processing, business 
& educational prog rams... and much, 
much more. 

So we're raising the price. Right? 

Wrong! All you pay is a small hook-up 
charge, and $5.00 per hour billed in minutes 
to your charge card. You need a 300 baud 
modem and we're a local phone call in 
more than 200 North American cities. 

Write for information. This is almost too 
good to believe, but we're delivering as 
promised. 



CompuServe 

Information Service Division 
5000 Arlington Centre Blvd. 
Columbus, Ohio 43220 
(614) 457-8600 



Circle 69 on inquiry card. 



BYTE August 1980 107 



No.15: 






lake a byte. 

Sollware lor most popular 8080/780' computer disk systems including 

NORTH STAR, iCOM, MICROPOLIS, DYNABYTE DB8/2 & DB8/4, EXIDY SORCERER, SD SYSTEMS, ALT AIR, 
VECTOR Ml, MECA, 8" IBM, HEATH H17& HB9, HELIOS, IMSAI VDP42 & 44, REX, NYLAC, INTERTEC SUPER-BRAIN 
VISTA V80 and V200, TRS-80' MODEL I and MODEL II, ALTOS, OHIO SCIENTIFIC, DIGI-LOG, KONTRON PSI-80, 
IMS 5000 diskette lormals and CSSN BACKUP cartridge tapes. 






Prices reflect distribution on B" s 




11 n (Drm.it is foouesled which roqu 




n surcharge at 18 |iur ntld.lio.nnl 




A surcharge ot *25 will bo nddoc 


for soliw.ul! on CSSN 






la 1100. 





CP/M ' VERSION 2 FOR TRS-80 MODEL II NOW AVAILABLE £***«** ^ ^j^ All Lifeboat programs require CP/M, unless otherwise stated. 



JSJ* 



MiaihI/ Alone 
□ CP/M" FLOPPY DISK OPERATING SYSTEM - Digital 
Research's operaling system configured for many 
popular mlcro-compulers and disk systems: 
System Version Price 

Norlh Star Single Density 1.4. ,. .146/25 v 

North Star Double Density 1.4 145/25 

North Star Double/Quad 2.x 170/25 

Durango F-85 2.x 170/25 

iCOM Micro-Disk 2411 1.4 145/25 

iCOM 3712 1.4... . 170/25 V* 

iCOM 3812 1.4... . 170/25 ' 

Mits 3202/Allair 8800 1.4.... 145/25 

Heath H8 + H17 1.4 145/25 m 

Heath H69 1.4 145/25 m 

Heath H09 by Magnolia 1.4 250/2S;} 

Heath H89 by Magnolia 2.x 300/250 

Onyx C8001 2.x . . . . 300/250 

TRS-80 Model I 1.4 145/25 m 

TRS-80 Model II 2.x... . 170/25 

TRS-80 Model II + Corvus 2.x 250/25 

Processor Technology Helios II ..1.4 145/25 

Cromemco Syslem 3 1.4 145/25 

Intel MDS Single Density 1.4 145/25 

Intel MDS Single Densily 2.x 170/25 

Micropolis Mod I 1.4 145/25 v 

Micropolis Mod II 1.4 145/25 v 

The following configurations are scheduled (or re- 
lease soon; 

Apple II SoftCard 2.x 350/25& 

North Slar Double/Quad + Corvus 2.x 250/25 

North Slar Horizon HD-1 2.x 250/25 

Ohio Scientific C3 2.X 200/25 

Ohio Scientific C3-C 2.x 250/25 

Micropolis Mod II 2.x 200/25 

Mostek MDX STD Bus System 2.x 350/25 " 

ICOM 3812 2.x 225/25 ' 

iCOM 4511/PerlecD3000 2.x 375/25" + 

Soltwaro consists ol the operating system, text edi- 
tor, assembler, debugger and other utilities for file 
management and system maintenance. Complete set 
ol Digital Research's documentation and additional 
implementation notes included. Systems marked ' 
and ** include firmware on 2708 and 2716. Systems 
marked + include 5440 media charge. Systems 
marked % require the special % versions ot software 
in this catalog. Systems marked v have minor variants 
available to suit console interlace ol system. Call or 
write lor full list of options. Includes hardware addi- 
tion to allow our standard versions ot software to run 
under It. 



DIGITAL RESEARCH 

Q MP/M - Installed for single density MDS-600. Multi- 
processing derivative of the CP/M operating system. 
Manual includes CP/M2 documentation . . . .$300/150 
Q MAC-8080 - Macro assembler. Full Intel macro deli- 
© nitions. Pseudo Ops include RPC, 1RP. REPT, TITLE. 
PAGE, and MACLIB. Produces absolute hex oulput 
plus symbol table file for use by SID and 2SID (see 
below) $120/515 

Q SID-80B0 — Symbolic debugger. Full trace, pass 
® count and breakpoint program testing. Has back- 
trace and histogram utilities. When used with MAC, 
provides full symbolic display of memory labels and 
equated values $105/515 ■* 

D ZSIO-Z80 - Symbolic debugger with all features of 
© SID $130/515 

® 

G TEX — Text output formatter to create paginated, 

© page-numbered and justified copy. Oulput can be 

directed to printer or disk $105/515 

□ DESPOOL — Utility program to permit simultaneous 
® printing from text files while executing other pro- 
grams $ao/*io 



□ 280 DEVELOPMENT PACKAGE-Consists of: (1) disk i 
Eg) file lino editor, with global inter and intra-llne faclli- I 
® lies; (2) 280 relocating assembler, Zllog/Mostek mne- ! 

monies, conditional assembly and cross reference 
table capabilities: (3) linking loader producing abso- 
lute Inlol hex disk file »95/$20 ,■ 

D ZDT-280 Monitor Debugger to break and examine 

f registers with standard Zilog/Mostek mnemonic dis- 
assembly displays. $35 when ordered with ZB0 Devel- 
opment Package $50/510 

AVOCET SYSTEMS 

□ XASM-68 — Non-macro cross-assembler with nested 
conditionals and full range of pseudo operations. As- 
sembles From standard Motorola MC6800 mnemonics 
to Intel hex I200/J25 

□ XASM-65 - As XASM-68 lor MOS Technology MCS- 
6500 series mnemonics S200/S2S 

..' □ XASM-48 - As XASM-68 lor Intel MCS-48 and UPI-41 
families $200/$25 

D XASM-18 - As XASM-68 for RCA 1802 $200/$25 

□ DISTEL - Disk based disassembler to Intel 8080 or 
TDL/Xltan Z80 source code, listing and cross refer- 
ence files, Intel or TDL/Xilan pseudo ops optional. 
Runs on 8080 $65/$10 

DDISILOG-As DISTEL to 2llog/Mostek mnemonic 
® files $65/*10 

D SMAL/B0 Structured Macro Assembler Language — 
® Package of powerful general purpose text macro 
processor and SMAL structured language compiler. 
SMAL is an assembler language with IF-THEN-ELSE, 
LOOP-REPEAT-WHILE, DO-END, BEGIN-END con- 
structs $75/$15 



J.ii-Jtl.' Al< 



,&*ty" 



P liny C — Interactive intorprelive system for teaching 
® structured programming techniques. Manual includes 

full source listings $105/(50 

D BDS C COMPILER - Supports most features of lan- 
u guage, including Slructures, Arrays, Pointers, recur- 
(0 sive function evaluation, overlays. Includes linking 
loader, library manager, and library containing gen- 
ii ■(.',(' ' , eral purpose, file I/O, and floating point functions. 
' |,iA* Lacks Initializers, sialics, floats and longs. Docu- 
;. [ ' monlation includes "The C PROGRAMMING LAN- 
GUAGE" by Kernighan and Ritchie $145/$25 

a WHITESMITHS C COMPILER - The ultimate In sys- 
© terns software tools. Produces faster code than a 
1 pseudo-coda Pascal with more extensive facilities. 
Conforms to the full UNIX' Version 7 C language, de- 
scribed by Kernighan and Ritchie, and makes avail- 
able over 75 functions lor performing I/O. string 
manipulation and storage allocation. Linkable to 
Microsoft REL files. Requires 60K CP/M .... $63O/$30 



Sim. 

i.l/ Alonr. 



■noil/ Alon* 



MICROSOFT 

D BASIC-80 - Disk Exlended BASIC, ANSI compatible 
■:i ■ with long variable names, WHJLE/WEND, chaining, 

m variable length (lie records $325/$25 

I j BASIC COMPILER - Language compatible with 
(0 BASIC-80 and 3-10 limes (aster execulion. Produces 
® standard Microsoft relocatable binary oulput. In- 
cludes MACRO-E0. Also linkable to FORTRAN-80 or 
COBOL-80 code modules $350/$25 



□ FORTRAN-BO 
(p many extensl 



ANSI 66 (except lor COMPLEX) plus 
is. Includes relocatable object com- 
iador, library with manager. Also in- 
cludes MACRO-80 (see below) $425/$25 

a COBOL-80 - Level 1 ANSI '74 standard COBOL plus 
(y most ot Level 2. Full sequential, relative, and In- 
@ dexed tile support with variable file names. STRING, 
UNSTRING, COMPUTE, VARYING/UNTIL. EXTEND, 
CALL. COPY, SEARCH, 3-dlmonslonal arrays, com- 
pound and abbreviated conditions, nested IF. Power- 
ful interactive screen-handling extensions. Includes 
compatible assembler, linking loader, and relocat- 
able library manager as described under MACRO-80 
$70O/$25 

□ MACRO-80 - 8080/Z80 Macro Assembler. Intel and 
© 2ilog mnemonics supported. Relocatable linkable 
,u, output. Loader, Library Manager and Cross Reler- 

ence List utilities Included $149/$15 

n XMACRO-88 — 8086 cross assembler. All Macro and 

® utility features of MACRO-80 package. Mnemonics 

slightly modified from Intel ASM86. Compatibility data 

sheet available $275/$25 

□ ED1T-80 — Very fasl random access text odilor for text 
© with or without line numbers. Global end inlra-line 

commands supported. File compare utility Included. 
$89/$15 



□ PASCAL/M" — Compiles enhanced Standard Pascal 
® to compressed efficient Pcode. Totally CP/M com- 
patible. Random access files. Both 16 and 32-blt Inte- 

,[') gers. Runllmo error recovery. Convenient STRINGS. 

,-.'. OTHERWISE clause on CASE. Comprehensive man- 

J--' ubI (90 pp, Indexed). SEGMENT provldos ovorlay 

' f structure. INPORT, OUTPORT and untyped files for 

arbilrary I/O. Requires 56K CP/M. Specify 1) 8080 

CP/M, 2) 280 CP/M, or 3) Cromemco CDOS . $1 75/$20 

L"J PASCAL/2 - Z80 native codo PASCAL compiler. Pro- 
CD duces optimized, ROMable re-entrant code. All inlcr- 
® lacing lo CP/M is through the supporl library. The 
package Includes compiler, relocating assombler and 
linker, and source for all library modules. Variant 
records, strings and direcl I/O are supported. Re- 
quires 56K CP/M $395/$25 

□ PASCAL/MT - Subset ol standard PASCAL. Gener- 
® ates ROMable 8080 machine code. Symbolic dobug- 

l ® ger Included. Supports Interrupt procedures, CP/M 
'-.,;' tile I/O and assembly language Interface. Real varl- 
,'> ables can be BCD, software floating point, or AMD 
9511 hardware floating point. Includes strings enu- 
(J meralions and record dale lypes. Manual explains 
,,.■.'■' BASIC to PASCAL conversion. Requires 32K. 

¥* S2SO/S30 

[~1 ALGOL-B0— Powerful block-structured language com- 
® pller featuring economical run-lime dynamic alloca- 
tion ol momory. Very compacl (24K total RAM) sys- 
tem implementing almost all Algol 60 report features 
plus many powerful extensions including string han- 
dling direct di3k address I/O etc $199/520 

D CBASIC-2 Disk Extended BASIC- Non-interactive 
6 BASIC wilh pseudo-code compiler and run-lime in- 
terpreter. Supports full file control, chaining. Integer 
and exlended precision variables, etc $120/$15 



MICRO FOCUS 

□ STANDARD CIS COBOL - ANSI 74 COBOL stand- 
CD ard compiler fully validated by U.S. Navy tosts lo 

ANSI level 1. Supports many lealures lo level 2 in- 
cluding dynamic loading ol COBOL modules and a 
full ISAM lile facility. Also, program segmentation, 
interactive debug and powertul interactive extensions 
to support protected and unprotected CRT screen 
formatting Irom COBOL programs used with any 
dumb terminal $850/$50 

□ FORMS 2 -CRT screen editor. Oulput Is COBOL dala 
® descriptions (or copying into CIS COBOL programs. 

Automatically creates a query and update program ol 
indexed files using CRT protected and unprotected 
screen formals. No programming experience needed. 
Output program directly compiled by STANDARD CIS 
COBOL $200/$20 



^Zww p^tcejf 



EIDOS SYSTEMS 

Q KISS - Keyed Index Sequential Search. Offers com- 
© plete Multi-Keyed Index Sequential and Direcl Ac- 
cess tile management. Includes built-in utility func- 
tions for 16 or 32 bit arithmetic, strlng/integerconvor- 
sion and string compare. Delivered as a relocatable 
linkable modulo in Microsoft format (or use wilh 

FORTRAN-80 or COBOL-80, etc $335/523 

D KBASIC - Microsoft Disk Extended BASIC version 

© 4.51 integrated by implementation of nine additional 

commands In language. Packago Includes KISS.REL 

as described above, and a sample mail list program. 

$585/$45 

To licensed usors ol Microsolt BASIC-80 (MBASIC) 
$435/$45 



□ XYBASIC Interactive Process Control BASIC - Full 
disk BASIC lealures plus unique commands lo handle 
byle rotate and shift and to test and set bits. Avail- 
able in several versions: 

Integer ROMable $350/$25 

Integer ROM squared 5350/525 

1 1 Integer CP/M $350/525 

' Exlended ROMable $450/525 

Extended ROM squared $450/$25 

Exlended CP/M $450/$25 

Extended Disk CP/M $550/525 

Integer CP/M Run Time Compiler 5350/525 

Extended CP/M Run Time Compiler $450/525 



D RECLAIM -A utility to valldale media under CP/M. 

Program lesls a diskette or hard disk surface for 

fii.i errors, reserving the imperfections In invisible files. 

■ and permilllng continued usage of the remainder. 

Essential lor any hard disk. Requires CP/M version 2. 

$80/$5 

fl BASIC UTILITY DISK -Consisls of: (1) CRUNCH-14 

9 — Compacting utility lo reduce Ihe size and increase 
the speed ol programs in Microsolt BASIC 4.51, 
BASIC-80 and TRS-80 BASIC. (2) DPFUN - Doublo 
precision subroutines for computing nineteen trans- 
cendental functions including square root, natural 
log, log base 10, sine, arc sine, hyperbolic sine, 
hyperbolic arc sine, etc. Furnished in source on 
dlskelte and documentation $50/S3S 

D STRING/80 - Character string handling plus roulines 
for direct CP/M BDOS calls from FORTRAN and Olher 
compatible Microsoft languages. The utility library 
contains roulines lhat enable programs lo chain lo 
a COM lile, retrieve command line parameters, and 
search (lie directories wilh full wild card lacilities. 
Supplied as linkable modules In Microsolt format. 
$95/$20 

□ STRING/80 source code available separately $295/NA 
HI THE STRING BIT - FORTRAN characler siring han- 
9 dling. Roulines to find, fill, pack, move, separate. 

concatenate and compare characler strings. This 
package completely eliminates Ihe problems asso- 
ciated wilh characler siring handling in FORTRAN. 
Supplied with source $65/$15 

□ VSORT — Versatile sort/merge system lor fixed length 
8 records with fixed or variable longlh fields. VSORT 

can be used as a stand-alone package or loaded and 
called as a subroutine from CBASIC-2. When used as 
a subrouline, VSORT maximizes Ihe use ol buller 
space by saving the TPA on disk and restoring II on 
completion of sorting. Records may be up to 255 
bytes long wilh a maximum ol 5 fields. Upper/lower 
case translation and numeric fields supported. 

$175/520 

C! CPM/374X- Has lull range of functions to create or 
re-name an IBM 3741 volume, display directory Infor- 
mation and edit the data sal contents. Provides lull 
(lie transfer facilities between 3741 volume data sels 

and CP/M files $195/510 

[~| BSTAM — Utility lo link one computer to anolher also 
5 equipped with BSTAM. Allows file transfers at full 
dala speed (no conversion to hex), wilh CRC block 
control chock lor very reliable error detection and 
automatic retry. We use III ll's greatl Full wildcard 
expansion lo send *.COM, elc. 9600 baud wilh wire. 
300 baud with phone connection. Both ends need 
one. Standard and ©versions can talk to one anolher. 
$150/510 



□ WHATSIT?" Interactive dala-base system using as- 
sociative lags lo retrieve Information by subject. 
Hashing and random access used (or last response. 
Requires CSASIC-2 5175/525 

□ SELECTOR lll-C2-Da!a Base Processor lo create 
t and mainlain mulli Key dala bases. Prints lormnlled 
■ij. sorted reports wilh numerical summaries or mailing 

labels. Comes with sample applications, including 
Sales Aclivlly, Inventory. Payables, Receivables. 
Check Register, and Client/Pa lien I Appointments, elc. 
Requires CBASIC-2. Supplied In source - . .5295/520 

□ GLECTOR - General Ledger option to SELECTOR 
III-C2. Interactive system providos for customized 
COA. Uniquo chart o( transaction types insure proper 
double entry bookkeeping. Generates balance sheets, 
P&L statements and journals. Two year record allows 
for statemen! ot changes In linancial position report. 
Supplied In source. Requires SELECTOR III-C2. 
CBASIC-2 and 56K system $350/525 



Pricesandspecillc; 



s subject to change without notice. 



Lifeboat Associates, 1651 Third Avenue, 



10028 (212) 860-0300 Telex: 220501 



□ CBS - Configurable Business System is a compre- 
f henslve set of programs for delining custom data files 
and application systems without using a program- 
ming language such as BASIC. FORTRAN, elc. Mul- 
tiple key fields for each data file are supported. Set-up 
program customizes system lo user's CRT and printer. 
Provides last and easy interaclive data entry and 
retrieval wilh transaction processing. Report genera- 
tor program does complex calculations with stored 
and derived data, record selection wilh multiple cri- 
teria, and custom formals. Sample Invenlory and mail- 
ing list systems included. No supporl language re- 
quired $295/540 



MICRO DATA BASE SYSTEMS 

D HDBS -Hierarchical Dala Base System. CODASYL 
oriented wilh FILEs, SETs, RECORDS and ITEMs 
which are all user defined. ADD, DELETE. UPDATE. 
SEARCH, and TRAVERSE commands supported. 
SET ordering is sorted, FIFO. LIFO, nexl or prior. 
One lo many set telalionship supported. Read/write 
proteclion al the FILE level. Supports FILEs which 
extend over multiple floppy or hard disk devices. 

□ MDBS - Micro Data Base Syslem. Full network data 
base with all lealures ol HDBS plus multi-level read/ 
write proteclion for FILE. SET. RECORD and ITEM. 
Explicil represenlalion of one to one, one lo many, 
many to many, and many to one SET relationships. 
Supports mulliple owner and multiple record types 
within SETs. HDBS files are fully compatible. 

□ HDBS-280 version 5250/540* ' 

D MDBS-280 version $750/$40** 

8080 version available at S75 extra. 
When ordering, specily one of Ihe language inter- 
faces listed below. Additional language interlaces 
available al time of purchase for $100 r $125 II 
purchased later. 

*. "The single manual covering HDBS and MDBS when 
purchased alone comes without specific language 
interlace manual. Manuals are available for the fol- 
lowing Microsoft languages: 

1) MBASIC 4.51, 2) BASIC-80 5.0, 3) Compiled BASIC 
or FORTRAN-80, 4) COBOL-80. 5) MACRO-80. 
5NA/$10 



MICROPRO 

D SUPER-SORT I - Sort, merge, exlract utility as abso- 
© lute executable program or linkable module in Micro- 
soft format. Sorts fixed or variable records wilh dala 
in binary, BCD, Packed Decimal, EBCDIC. ASCII, 
floating & fixed poinl, exponential, field Justified, etc. 
Even variable number ol fields per record! $225/525 

□ SUPER-SORT II -Above available as absolute pro- 
© gram only $175/525 

D SUPER-SORT III -As II without SELECT/EXCLUDE 
© $125/$25 

□ DATASTAR— Professional forms control entry and 
© display system lor key-to-dtsk data capture. Menu 

, driven with built-in learning aids. Inpul field verifica- 
,/ lion by length, mask, attribute (i.e. upper case, lower 
PS) case, numeric, auto-dup. etc.). Built-in arithmetic 
capabilities using keyed data, constant and derived 
values. Visual feedback lor ease of forms design. 
Files compatible with CP/M-MP/M supported lan- 
guages. Requires 32K CP/M 5350/535 

□ WORD-STAR — Menu driven visual word processing 
© system lor use wilh slandard terminals. Text format- 
ting performed on screen. Facilities tor lext paginale, 
page number, justify, cenler and underscore. User 
can print one documenl while simultaneously editing 
a second. Edit facililics include global search and 
replace. Read/Write to olher lext tiles, block movo. 
etc. Requires CRT terminal wilh addressable cursor 
positioning 5445/S40 

□ WORD-STAR Cuslomization Nolcs-For sophislicaled 
users who do not have one ol Ihe many standard 
terminal or prinler configurations In the distribution 
version of WORD-STAR NA/$95 

□ WORD-MASTER Tex! Edilor - In one mode has supor- 
© set ol CP/M's ED commands including global search- 
ing and replacing, forwards and backwards in tile in 
video mode, providos lull screen editor for users wilh 
serial addressable-cursor terminal 5145/525 

fl TEXTWRITER III - Text formailer lo justify and pagi- 
® nate lellers and other documents. Special features 
include insertion of texl during execulion Irom olher 
disk files or console, permitting recipe documents 
to be created from linked fragments on olher files. 
Has facililies for sorted index, lable ol contents and 
footnote insertions. Ideal for conlracls, manuals, etc. 
Now compatible wilh Electric Pencil" prepared files. 
$125f$20 

SA5/C wC&l/jMZZl-- 

PEACKTREE SOFTWARE " 

□ GENERAL LEDGER - Records details of all linancial 
© transactions. Generates a balance- sheet and an in- 
t come statement. Flexible and adaplable design lor 

both small businesses and lirms perlorming client 
writoup services. Produces reports as follows: Trial 
Balance. Transaction Registers. Balance Sheet. Prior 
Year Comparative Balance Sheet, Income Statement, 
Prior Year Comparative Income Statement and De- 
partment Income Statements. Interaclive wilh olher 
PEACHTREE accounting packages. Supplied in 
source code for Microsoft BASIC $990/530 



'"The Software Supernwker is a trademark of Lifeboat Associates 






P ACCOUNTS PAYABLE- Tracks current and aged 
© payables and incorporates a check writing feature. 
t Maintains a complete vendor file with intormalion on 
purchase orders and discount terms as well as active 
account status. Produces reports as follows: Open 
Voucher Report, Accounts Payable Aging Report and 
Cash Requirements. Provides input to PEACHTREE 
General Ledger. Supplied in source code for Micro- 
soil BASIC $990/$3O 

□ ACCOUNTS RECEIVABLE - Generates Invoice legis- 
(p ler and complete monthly statements. Tracks current 

t and aged receivables. Maintains customer file includ- 
ing credit information and account status. The cur- 
rent status of any customer account is instantly avail- 
able. Produces reports as folljws: Aged Accounts 
Receivable, Invoice Register, Payment and Adjust- 
ment Register and Customer Account Status Report. 
Provides input to PEACHTREE General Ledger. Sup- 
plied in source code for Microsoft BASIC . .$990/$3O 

□ PAYROLL - Prepares payroll for hourly, salaried and 
© commissioned employees. Generates monthly, quar- 
t terly and annual returns. Prepares employee W-2's. 

Includes fables for federal withholding and FICA as 
well as withholding for all 50 slates plus up to 20 
cities from pre-computed or user generated tables. 
Will print checks. Payroll Register, Monthly Summary 
and Unemployment Tax Reporl. Provides input to 
PEACHTREE General Ledger. Supplied in source 
code for Microsoft BASIC $99G/$30 

□ INVENTORY - Maintains detailed information on 
© each inventory item including part number, descrip- 

t tion, unit of measure, vendor and reorder data, Item 
activity and complete information on current item 
costs, pricing and sales. Produces reports as follows: 
Physical Inventory Worksheet, Inventory Price List, 
Departmental Summary Report, Inventory Status Re- 
port, The Reorder Report and the Period-to-Date and 
Year-to-Date reports. Supplied in source code for 
Microsoft BASIC S11907S30 



GRAHAM-DORIAN SOFTWARE SYSTEMS 

□ Comprehensive accounting software written in 
© CBASIC-2 and supplied In source code. Each soft- 
<S) ware package can be used as a stand-alone system 
f or integrated with the General Ledger for automatic 

posling to ledger accounts. Requires CBASIC-2. 

GENERAL LEDGER $995/$35 

ACCOUNTS PAYABLE $995/535 

ACCOUNTS RECEIVABLE $995/$35 

INVENTORY SYSTEM $590/$35 

JOB COSTING $995/535 

APARTMENT MANAGEMENT $5907535 

CASH REGISTER $590/535 

G POSTMASTER — A comprehensive package for mail 
(Bi list maintenance that is completely menu driven. 
Features include keyed record extraction and label 
. production. A form letter program is included which 
fo provides neat letters on single sheet or continu- 
ous forms. Compatible with NAD files. Requires 
CBASIC-2 $150/515 

STRUCTURED SYSTEMS GROUP 

D GENERAL LEDGER - Interactive and flexible syslem 
7 providing proof and report outputs. Customization of 
COA created interactively. Multiple branch account- 
ing centers. Extensive checking performed at data 
entry for proof, COA correctness, etc. Journal entries 
may be batched prior to posting. Closing procedure 
automatically backs up input files. Now includes 
Statement of Changes in Financial Position. Requires 
CBASIC-2 $1250/525 

□ ACCOUNTS RECEIVABLE -Open item syslem with 
t output for internal aged reports and customer-ori- 
ented statement and billing purposes. On-Line En- 
quiry permits information for Customer Service and 
Credit departments. Interface to General Ledger pro- 
vided if both systems used. Requires CBASIC-2. 
$1250/525 

□ ACCOUNTS PAYABLE- Provides aged statements 
t of accounts by vendor with check writing for selected 

invoices. Can be used alone or with General Ledger 

and/or with NAD. Requires CBASIC-2 $1250/525 

Q PAYROLL- Flexible payroll system handles weekly, 
t bi-weekly, semi-monthly and monthly payroll periods. 
Tips, bonuses, reimbursements, advances, sick pay, 
vacation pay, and compensation time are all part of 
the payroll records. Prints government required peri- 
odic reports and will post to multiple SSG General 
Ledger accounts. Requires CBASIC-2 and 54K of 

memory $1250/$25 

Q INVENTORY CONTROL SYSTEM - Performs control 
t functions of adding and depleting stock items, add- 
ing new items and deleting old items. Tracks quantity 
of items on hand, on order and back-ordered. Op- 
tional hard copy audit trail is available. Reports in- 
clude Master Item List, Stock Activity, Stock Valua- 
tion and Re-order List, Requires CBASIC-2 $1250/$25 

□ ANALYST - Customized data entry and reporting sys- 
t tern. User specifies up lo 75 data items per record. 

Interactive data entry, retrieval, and update facility 
makes information management easy. Sophisticated 
report generator provides customized reports using 
selected records with multiple level break-points for 
summarization. Requires a disk sort utility such as 
QSORT, SUPER-SORT or VSORT and CBASIC-2. 
$250/$15 

□ LETTERIGHT - Program to create, edit and type let- 
ters or other documents. Has facilities to enter, dis- 
play, delete and move text, with good video screen 
presentation. Designed to integrate with NAD for 
form letter mailings. Requires CBASIC-2 . .$200/$25 

□ NAD Name and Address selection system — Interac- 
tive mail list creation and maintenance program with 
output as full reports with reference data or restricted 
information for mail labels. Transfer system for ex- 
traction and transfer of selected records to create 
new files. Requires CBASIC-2 $100/520 

□ QSORT - Fast sort/merge program for files with fixed 
record length, variable field length information. Up to 
five ascending or descending keys. Full back-up of 
inpul files created $100/$20 



*• ** •* *• 

CONDIMENTS 

□ HEAD CLEANING DISKETTE-Cleans the drive Read/ 
Write head in 30 seconds. Diskette absorbs loose 
oxide particles, fingerprints, and other foreign parti- 
cles that might hinder the performance of the drive 
head. Lasts at least 3 months with daily use. Specify 
5" or 8". 

Single sided $20 each/$55 for 3 

Double sided $25 each/$65 lor 3 

□ FLIPPY DISK KIT - Template and instructions to 
modify single sided 5V.%" diskettes for use of second 
side in single sided drives $12.50 

□ FLOPPY SAVER - Protection (or center holes of 5" 
and 8" floppy disks. Only 1 needed per diskette. Kit 
contains centering post, pressure tool and tough 
7 mil mylar reinforcing rings for 25 diskettes. 

5", Kit J14.95 

5", Rings only $7.95 

8", Kit $16-95 

8", Rings only $6.95 

Q PASCAL USER MANUAL AND REPORT - By Jensen 
and Wirlh. The standard textbook on the language. 
Recommended for use by Pascal/Z, Pascal/M and 
Pascal/MT users $12 

□ THE C PROGRAMMING LANGUAGE - By Kernlghan 
and Ritchie. The standard textbook on the language. 
Recommended for use by BDS C, tiny C, and White- 
smiths C users $12 

□ STRUCTURED MICROPROCESSOR PROGRAMMING 
- By the authors of SMAL/80. Covers structured pro- 
gramming, the 8080/B085 instruction set and the 
SMAL/80 language MO 

□ ACCOUNTS PAYABLE & ACCOUNTS RECEIVABLE- 
CBASIC - By Osborne/McGraw-Hill $20 

□ GENERAL LEDGER-CBASIC- By Osborne/McGraw- 
Hill $20 

D LIFEBOAT DISK COPYING SERVICE - Transfer data 
or programs from one media format to another at a 
moderate cost from $25 

• * *• ** ** 

Hearty Appetite. 

"CP/M and MP/M are trademarks of Digital Research. 
Z80 is a trademark of Zllog, Inc. 
UNIX is a trademark of Bell Laboratories. 
WHATSIT? is a trademark of Computer Headware. 
Electric Pencil Is a trademark of Michael Shrayer 
Software. 

TRS-80 is a trademark of Tandy Corp. 
Pascal/M is a trademark of Sorcim. 

tRecommended system configuration consists of 48K 
CP/M, 2 full size disk drives, 24 x 80 CRT and 132 
column printer. 

® Modified version available for use wilh CP/M as im- 
plemented on Heath and TRS-80 Model I computers. 

©User license agreement for Ihis product must be 
signed and returned to Lifeboat Associates before 
shipment may be made. 

©©This product Includes/eXcludes the language manual 
recommended in Condiments. 

(DSerial number of CP/M system must be supplied with 

orders. 
©Requires Z80 CPU, 



NEW! NEW! NEW! 
NEWSLETTER 
FROM LIFEBOAT 



• Latest Version 
Numbers List 
of Software 

• Update on 
CP/M Users Group 

• The Great ZOSO Speaks 

Out from Behind the Scenes 

$18 PPd. for 12 issues (U.S., Canada, 
Mexico). Elsewhere $40. 
Send Check to "Lifelines," 1651 Third Avenue, 
New York, N.Y. 10028 or use your VISA or 
Mastercharge-ca\i (212) 722-1700 



I Copyright © 1980 Lifeboat Associates. No 
portion of this advertisement may be repro- 
duced without prior permission. 



Ordering Information 

MEDIA FORMAT ORDERING CODES 
When ordering, please specify formal code. 

LIFEBOAT ASSOCIATES MEDIA FORMATS LIST 

Diskette, cartridge disk and cartridge tape format codes to bB specified 
when ordering software for listed computer or disk systems. All sollware 
products have specific requirements in terms ol hardware or software 
support, such a MPU type, memory size, support operating system or 
language. 



Computer system Formil Coda 

Allalr B800 fl-.v . Sen M1TS 3200 

Alios - .-A1* 

Applo + Microsoft SollCard , RO 

BASF Systirn 7:00 BD 

Blackhawk S-noJe Density ... 03 

Blackhawk Mlcropoi:s Mod II 02 

CDS Versatile 3B . Q1 

CDS Versatile 4 02 

COMPAL-B3 .02 



Form*! Code 



) Z2D . 



CSSN BACKUP (tape) 



, ,R8 
-Tiff 



Digital Microsystem 
Disc 



« DlBCUa 



Ouranoo F.85 . 

Dynabyte DB8/2 H1 

Dynabyte DB8/4 AI' 

E*1dy Sorco^er + Uleboe! CP.'M . .0? 

Exldy Sorcerer - E.idy CP/M 04 

Healh HB 4 H17/H27.. P4 

Healh 89 + Litebcet CP/M P4 

HoBth 89 + Magnolia CP/M P7 

Hallos II .. See Processor (.■ ■ ■ 

Horlion Sae North Si. 

ICOM 2411 Micro Floppy R3 

ICOM 3712 

ICOM 3812 

ICOM 4511 5440 Cerlfldge CP/M 1.4 D1# 

iCOM 4511 5440 Cartridge CP/M 2.2 D2# 

IMS 500O RA 

IMS B000 
IMSA1 VDP-40 
IMSAI VOP-42 



Computer system 

RAIR Oouble Density HE 

Research Machines 8" Ai 

Reiearch Msctilnea 5W " . , RN 

REX . 03 

SO Systems B" . . AI * 

SO Syslsmi 5W" R3 

Sorcerer See Eiidy Sorcerer 

Soscebyte -AI 

SuperBreln .See Inieriec 

Terbell A1* 

TEl 5tt" -A3 

TEI B" AI* 

Thlnkerloys See Morrow Olscul 

TRS-80 Model I 5V." ...R2 

THS-80 Model I + FEC Freedom . . -RN 
THS-B0 Model I + M.cromauon .. A4* 
TRS-80 Model 1 + OmiHron iV," . RM 
TRS-80 Model 1 ■+ OmlWon 8" . . , . AI 
TRS-80 Model I 4 Shutlleboerd 8" ,A1 

TRS-80 Model It AT 

VDP.40/42/44/80 See IMSAI 

Vector MZ QJ 

Versatile See CDS Versatile 

Viste V80 5V t " Single Dens-ly . . P5 
Vine V200 SV." Double Density ..,.P8 

Zenith ZB9 -I- Llleboat CP/M P4 

Zenith ZBB + Magnolia CP/M P7 




Prices F.O.B. New York. 
Shipping, handling and C.O.D, 
charges extra. 
Manual cost applicable against 

of subsequent software 
purchase. 

The sale of each proprietary 
software package conveys a 
license for use on one 
system only. 



0FTWARE 
SUPER- 
MARKET 



VISA'- 




®w 



space for comments costly in disk 
space and load time, discouraging 
good program layout. For these 
reasons, there is increasing interest in 
changing to a directory file system. 
Perhaps it will be written on top of 
the screen system currently in use. 

The most important criticism of 
FORTH is that its source programs 
are difficult to read. Some of this 
impression results from unfamiliarity 
with a language different from others 
in common use. However, much of it 
results from its historical develop- 
ment in systems work and in read- 
only-memory-based machine control, 
where very tight programming that 
sacrifices clarity for memory 
economy can be justified. Today's 
trend is strongly toward adequate 
commenting and design for readabili- 
ty- 

FORTH benefits most from a new, 
different programming style; tech- 
niques blindly carried over from 
other environments can produce 
cumbersome results. Most FORTH 
programmers seldom use named 
variables; they use the stack instead 
so that the implicit commenting nor- 
mally available through choice of 
variable names is only provided 
through comments and user-defined 
operation names. Single definitions 
that would have more than about 
three unrelated numbers on the stack 
at any one time are best split into two 
or more operations; most program- 
mers learn to keep their definitions 
short. 

FORTH enforces extreme 
modularity, so the decomposition of 
each task into component parts is 
critical. Top-down design is especial- 
ly important. Large jobs should be 
written as application-oriented 
libraries of operations to make team- 
work and maintenance easier. A 
much larger fraction of the total pro- 
gramming effort is spent on design, 
with less on coding and debugging. 
For these and other reasons, FORTH 
creates its own issues of style, which 
are only beginning to be explored. 

A Taste of FORTH 

FORTH is an interactive language 
best explained by example. Because 
of this, a series of listings (listings 1 
thru 10) with fairly detailed explana- 
tions make up the rest of this article. 
In the listings that follow, underlining 
denotes user keyboard input. 

August 1980 © BYTE Publications Inc 109 



FORTH uses punctuation in some of its 
words, which makes representing them in 
text a difficult problem. For example, one 
FORTH word is ("), which could be taken 
to mean one of several character combina- 
tions. (For your information, the word has 
three characters and is made from a left 
parenthesis followed by a double quote 
mark and a right parenthesis.) 

To decrease the chance of confusion 
while trying not to clutter text unnecessari- 
ly, we will sparingly use braces, { }, to 
isolate the character string within as a 
FORTH word or phrase. (For example, the 
above word would be written { (") } .) 
Braces will be used only under the follow- 
ing situations: 

• when the material being quoted is a 



phrase of FORTH words (eg: { 26 
LOAD } or { 3 5 + } ) 

• with the FORTH words { . } (period), 
{ , } (comma), { : } (colon), { ; } 
(semicolon) , { 1 } (question 
mark), { ! } (exclamation 
point), { ' } (single quote mark), 
and { " } (double quote mark) 

• with any word using the above punctua- 
tion marks (eg: { $. } or { ." } ). 

All other FORTH words will be set apart 
by a space on either side of the word. So, in 
this and other FORTH articles in this issue, 
braces will always signal a FORTH word or 
phrase. The braces are not part of the word 
or phrase, and FORTH words will never 
use braces within the body of a figure or 
listing.. ..GW 



64KB RAM MEMORIES 

LSI-11 - $750.00 • SBC 80/10 - $750.00 
S-100 - $750.00 • 6800 - $750.00 • 6800-2 - $995.00 



||ll 11*11 

|{i§||i:I|| 

III I I 19 91 



CI-6800-2 64K x 9 




CI-S100 64Kx8 




CI-1103 32Kx 16 




CI-6800 64K x 8 




CI-8080 64K x 8 



CI-6800-2 — 16KB to 64KB. Plugs 
directly into Motorola's EXORciser I or 
II. Hidden refresh up to 1.5 Mhz. Cycle 
stealing at 2 Mhz. Addressable in 4K 
increments with respect to VXA or 
VUA. Optional on Board Parity. 64K x 9 
$995.00. 

CI-S100 — 16KB to 64KB. Transparent 
hidden refresh. No wait states at 4 Mhz. 
Compatible with Alpha Micro and all 
Major 8080, 8085 and Z80 Based S100 
Systems. Expandable to 512 K bytes 
thru Bank Selecting. 64K x 8 $750.00. 

CI-1103 — 16KB to 64KB on a single 
dual height board. On board hidden 
refresh. Plugs directly into LSI 11/2, 
H11 or LSI 11/23. Addressable in 2K 
word increments up to 256 K Bytes. 8K 
x 16 $390.00. 32K x 16 $750.00. 

CI-6800 — 16KB to 64KB on a single 
board. On board hidden refresh. Plugs 
directly into EXORciser I and compati- 
ble with Rockwell's System 65. 
Addressable in 4K increments up to 
64K. 16K x 8 $390.00. 64K x 8 $750.00. 

CI-8080 — 16KB to 64KB on a single 
board. Plugs directly into MDS 800 and 
SBC 80/10. Addressable in 4K 
increments up to 64K. 16 KB $390.00. 
64K $750.00. 



€ 



Test and burned-in. Full year warranty. 

Chrislin Industries, Inc. 

Computer Products Division 

31352 Via Colinas • Westlake Village, CA 91361 • 213-991-2254 



On the Necessity of Using 
Camera-Ready Copy 

Examination of listings 1 thru 10 will 
reveal a variety of typefaces used. This 
variety is present because each listing 
was created by the printer of the 
system producing the listing. Such 
listings are called camera-ready copy, 
which means that we can reproduce 
them in BYTE without inadvertently 
adding the errors that creep in with the 
retyping of a listing. Contributors to 
BYTE and onComputing are strongly 
encouraged to submit camera-ready 
listings made with a fresh ribbon, since 
this helps us to improve the accuracy 
of the article. 



Listing 1: FORTH as a calculator. FORTH 
is easy to approach because it can be used 
as a calculator. Here, the programmer has 
not defined any new operation but has 
used addition, multiplication, and print 
(the dot means print). These are three of 
about one hundred operations that are 
available when FORTH first comes up. 
Programming consists of defining new 
operations which can be custom designed 
for a particular task or a particular 
industry. 

FORTH uses postfix (also called RPN or 
reverse Polish notation) arithmetic, which 
is best known from its use in Hewlett- 
Packard calculators. In postfix notation, 
the operations are written after their 
arguments, not between them. The text of 
this article shows how postfix notation 
works, using a data structure called the 
stack, and it explains the formulas in this 
example. , 

Postfix notation, which does not use 
parentheses, is more general than 
ordinary arithmetic notation. Its biggest 
advantage is that it greatly simplifies the 
writing and calling of subroutines. 

In these examples, underlining indicates 
what the user has typed on the terminal. 
FORTH does not process the line until 
you type a carriage return. The OK 
prompt means that the system has com- 
pleted its work and is ready for new input 
from the user. 



2 


3 


+ 




s 


OK 






4 


5 


+ 


6 


/ 


+ * 


117 


OK 



Listing 2: Changing number bases. 
FORTH can work in different number 
bases and can change any time, so it 
serves as an octal/ hexadecimal/ 
binary/ decimal calculator within the 
limits of 16-bit numbers (or 32 bits for 
double precision). The FORTH word HEX 
converts FORTH into a hexadecimal 
machine, and all numbers are printed in 
Listing 2 continued on page 112 



110 August 1980 © BYTE Publications Inc 



Circle 70 on inquiry card. 




=£= = = : = =-; s s =-:: 

_"rhiipfif 



WASHINGTON, D.C. 

D.C. ARMORY/STARPLEX 

THURSDAY-SUNDAY 

SEPTEMBER 18-21 

11 A.M. TO 9 P.M. THURS.-SAT. 
11 A.M. TO 5 P.M. SUN. 



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The new computers are showing off. 
Over $50 million worth of equipment in over 100,000 
square feet of space, including the latest software and hard- 
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thing the NCC show has and more will be on display, and you can 
buy it all right on the spot. 

Computers costing $150 to $250,000, mini and micro com- 
puters, data- and word-processing equipment, telecommunica- 
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and Apple will all be there. 
There'll be conferences on business uses of small to 
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There'll be robots, computerized video games, 
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Everyone from kids to people who earn their liv- 
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Admission for adults is $5. The public is 
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S^sr Don't miss the computer show that 

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CHICAGO 

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thursday-sunday 

OCTOBER 16-19 

11 A.M. TO 9 P.M. THURS.-SAT. 

11 A.M. TO 5 P.M. SUN. 



s = :s- 


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Produced by National Computer Shows, 

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Telephone (617) 739-2000. 



Please send me: 



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PRUDENTIAL CENTER 

THURSDAY-SUNDAY 

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Listing 2 continued: 

hexadecimal until some other operation 
changes the base again. FORTH always 
begins a session in decimal radix. 

The operations DECIMAL and HEX are 
built into the system; OCTAL , 
BINARY , and TRINARY (base 3) are 
not. So when OCTAL was first used, the 
error message { OCTAL 1 } indicated 
an undefined word; that is, the system did 
not recognize the word OCTAL . In the 
next line, the user defined OCTAL (line 
6). This example illustrates FORTH's 
extensibility; users can extend the 
language to include new operators. 

Incidentally, the second error message 
{ 12885 ? } in line 12 resulted because 
the system was in binary (from the line 
above), and, in binary, numbers must 
contain only the digits and 1 , so 12885 
was not recognized as a number. It was 
treated as a word, and, because there was 
no operation named 12885 , the error 
message was generated. 

OCTAL and the other number-base 
operations work by giving a new value to 
BASE , a variable used by the system. 
Defining new operations is more fully 
explained in listing 3. The { ! } operation 
(store) is explained later. 

Number bases only affect input and 
output. All internal computation is in 
binary, so there is no speed penalty for 
using nondecimal numeric bases. 



HEX OK 

3BE8 C8 + . 3CB0 OK 

25 2F * . 6CB OK 



DECIMAL 1348 HEX . 541 OK 

DECIMAL 1348 OCTAL . OCTAL ? 

: OCTAL 8 BASE ! ; OK 

DECIMAL 1348 OCTAL . 2504 OK 

DECIMAL OK 

: BINARY 2 BASE ! ; OK 

: TRINARY 3 BASE ! ; OK 

12885 BINARY . 11001001010101 OK 

12885 BINARY . 12885 ? 

DECIMAL 12885 BINARY . 11001001010101 OK 

D ECIMAL 12885 OCTAL . 31125 OK 

DECIMAL 12885 HEX . 3255 OK 

DECIMAL 12885 TRINARY . 122200020 OK 

DECIMAL -12885 TRINARY . -122200020 OK 

DECIMAL OK 




TRUE BRANCH: 
EXECUTED IF 
N*0 



FALSE BRANCH- 
EXECUTED IF 
N = 



(a) 



I N IS ASSUMED | 

H TO BE ON TOP | 

I OF STACK I 

1 I 



"l 


TRUEOO) 






A 




D 












B 




E 












C 






" % 






t ' 


(b) 







Figure 2: An explanation of the 
IF ... ELSE ... THEN construct. (See 
listing 4.) As shown in figure 2a, the por- 
tion of code executed depends on the 
value of the number on top of the stack 
when the word IF is encountered. If we 
call this number N and say that the 
number has a boolean value of true if its 
numeric value is nonzero and false if 0, 
then figure 2b gives the equivalent con- 
struct to figure 2a in conventional 
flowchart notation. Here and in figures 3 
thru 5, the dotted box indicates the boun- 
daries of the construct (as opposed to 
values assumed to be on the stack). 



Listing 3: Defining new operations. Here, a new operation CUBE is created. CUBE 
replaces whatever number is on top of the stack with the cube of that number. The 
statements within the parentheses are comments. 

The colon, { : j, begins a FORTH word definition; the word following it is the name 
being defined. Semicolon, { ; }, ends the definition. 

The new word CUBE will first execute DUP, which duplicates the number on top of 
the stack, making a second copy. The second DUP leaves three copies. The first * causes 
the top two copies to be replaced by the square of the number; the next * computes the 
cube, and then all three copies of the original number are gone, leaving the cube of the 
number on top of the stack. 

This colon definition shows one of several ways to create new words in FORTH. 
Most words that appear inside the definition are compiled and not executed immediate- 

ly. 

All words and numbers in FORTH are separated by one or more blanks (and/or car- 
riage returns). FORTH operation names can be up to thirty-one characters long and can 
consist of letters, numbers, or any other characters. For example, an operation name 
could be a number, or it could be nonprinting characters only. In practice such names 
are rarely used, but they illustrate the flexibility that is available. 

Listing 3 continued on page 114 



112 August 1980 © BYTE Publications Inc 




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Listing 3 continued: 

This listing shows CUBE being executed from the terminal. It can also be used as a 
component in further definitions. A fundamental property of FORTH is that operations 
defined by users are indistinguishable from those which were originally part of the 
system. 



CUBE 
PUP DU 



N -> N. CUBE A NUMBER) 

( NOW THERE ARE THREE COPIES) 



GET THE CUBE) 



; OK 
5 CUBE . 125 OK 
-28 CUBE . -21952 



OK 



HEX 17 CUBE BINARY . DECIMAL 10111110000111 OK 



Listing 4: Conditional branching. The IF ... THEN is for conditional execution. IF takes 
one argument off of the stack; this argument is interpreted as a boolean or truth value, 
with meaning false and any nonzero value meaning true. If true, any statements be- 
tween the IF and THEN are executed. In either case, execution continues after the 
THEN , which terminates the conditional. There is also an optional ELSE clause that is 
executed only if the argument is false. (See figure 2.) 

. Here, the true-clause co)itains only one word, MINUS , but it could contain almost 
any FORTH statements, including other conditionals and loops nested to any practical 
depth. These statements run fast because they are compiled into a form of object pro- 
gram called threaded code. 

Incidentally, the FORTH word 0< returns a boolean value indicating whether its 
argument (the number on top of the stack) is less than zero. The DUP is necessary 
because 0< follows the FORTH convention that operations should destroy their 
arguments on the stack. MINUS reverses the sign of its argument (the top stack 
number). 

Iterns in parentheses are comments. The comment "N — > N" in the first line is to 
show that this operation takes one number off of the stack and returns one number to it. 
Perhaps the most important information to put in the comments accompanying each 
new operation is what arguments it takes off of the stack and what results it returns to 
the stack. 



ABSOLUTE-VALUE ( N -> N. ABSOLUTE VALUE) 



DUP 0< ( GET BOOLEAN. TRUE IF NEGATIVE) 
IF MINUS THEN ( NEGATE THE NUMBER IF TRUE) 
; OK 

10 ABSOLUTE-VALUE . 10 OK 

-5 ABSOLUTE-VALUE . 5 OK 



Listing 5: The DO ... LOOP, a structured loop with a counting index. DO takes two 
arguments from the stack, the initial value of the index (on top) and the final value plus 
1. (See figure 3.) These indices are written in reverse order from most other languages, 
making the loop terminating value (which is more often passed as an argument) more 
accessible on the stack. 

CR simply performs a carriage return. In this example, the index values are literals (10 
and 0), but they can also come from variables or from computations of any complexity; 
anything that gets the indices onto the stack is legitimate. 

This listing also shows a timing benchmark; the word TIME-TEST does 30,000 empty 
loops. On an Apple II running FORTH, TIME-TEST executes in less than 4 seconds. In 
Apple Integer BASIC (which is a fast BASIC), 30,000 empty loops take 40 seconds. 

: 10CUBES ( ->. PRINT A TA8LE OF CUBES OF 0-9) 



10 Q 



INDICES OF LOOP) 



_DQ_ 



CR I 



( START LOOP) 



I CUBE 



LOOP ( END OF LOOP) 
; OK 
lOCTJBES 



1 1 

2 8 

3 27 

4 64 

5 125 
5 216 

7 343 

8 512 

9 729 OK 

: TIME-TEST 30000 DO LOOP 
TIME-TEST OK 



PRINT A NUMBER AND ITS CUBE) 



OK 



114 August 1980 © BYTE Publications Inc 




I 



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Listing 6: The BEGIN . . . UNTIL loop. This loop takes one argument, a truth value, 
usually computed within the loop, at the end. If it is false (O), control branches back to 
the corresponding BEGIN ; if the value is true (nonzero), the loop ends, and control 
transfers to the next word in the program. (See figure 4.) 

Note that the test of the value on top of the stack occurs at the end of the body of the 
loop; this guarantees that the body of the loop will be executed at least once. 

The word = removes the top two numbers from the stack and returns a truth value 
of 1 if they are equal, O otherwise. In this example, the index stays on the stack and is 
duplicated before each use. The DROP at the end throws away the top stack value; this 
prevents the used index from cluttering the stack. 

The warning message "10CUBES ISN'T UNIQUE" notifies us that the same name has 
already been defined. The only penalty for reusing a name is that the former definition 
becomes inaccessible for the rest of the program. Therefore, you do not have to 
remember a list of reserved words in FORTH; if you do not know about a name or have 
forgotten about it, you probably were not planning to use it anyway. But, in case of a 
mistake, the bad definition can be deleted with a FORGET operation, or the source code 
can be changed on disk. 

/Some versions of FORTH use BEGIN ... END instead of 
BEGIN ... UNTIL .... GW/ 

: 10CUBES ( ->. SAME, USING 'UNTIL 1 LOOP) 10CUBES ISN'T UNIQUE 



( INITIAL VALUE OF INDEX) 
BEGIN ( START LOOP) 

CR PUP . PUP CUBE . ( PRINT A I AND ITS CUBE) 



1 + 



PUP 10 



UNTIL 



( INCREMENT) 

( TEST FOR INDEX=10) 



ENO OF LOOP 



PROP 



THROW AWAY USEO INDEX) 



• OK 


10CDBES 





1 1 


2 8 


3 27 


4 64 


5 125 


6 216 


7 343 


8 512 


9 729 



Listing 7: The BEGIN ... WHILE ... REPEAT loop. This looping structure tests the 
value on top of the stack at the beginning of the loop; because of this, this loop can ex- 
ecute times. REPEAT causes an unconditional branch back to BEGIN , and WHILE 
branches out of the loop (just beyond REPEAT ) if the truth-value which it finds on top 
of the stack is false (ie: 0); see figure 5. 

All of these looping and conditional branching structures can be nested within each 
other to any practical depth. Any mismatching can be detected at compile time. Most 
FORTH systems allow these structures only inside colon definitions; they cannot be 
executed directly from the terminal. 

(Some versions of FORTH use: BEGIN ... IF ... WHILE or 
WHILE ... PERFORM ... PEND instead of BEGIN ... WHILE ... REPEAT .... GWj 

: 10CUBES ( ->. SAME, USING 'WHILE' LOOP) 10CUBES ISN'T UNIQUE 
( INITIAL VALUE OF INPEX) 



BEGIN 

PUP 10 < ( LOOP TEST) 
WHILE 



CR PUP . PUP CUBE . ( PRINT A # ANP ITS CUBE) 
1 + ( INCREMENT) 
REPEAT 



DROP ( THROW AWAY USED INDEX) 
T_~0~K 
10CUBES 



1 1 

2 8 

3 27 

4 64 

5 125 

6 216 

7 343 

8 512 

9 729 OK 



116 August 1980 ® BYTE Publications Inc 



# 



^ 




MPI 

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IMPACT 

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PRINTER 



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BYTE August 1980 117 



1 + ENDING VALUE 
OF LOOP VARIABLE 



BEGINNING VALUE 
OF LOOP VARIABLE 




BODY OF LOOP; WITHIN 
LOOP, FORTH WORD "I" 
HAS VALUE OF LOOP 



LOOP VARIABLE, I, IS INCREMENTED, 
IF I <L, CONTROL TRANSFERS TO "DO"; 
IF I >L, CONTROL TRANSFERS TO FIRST 
WORD AFTER "LOOP" 

[a) 



BEGIN 

A 

UNTIL 



-BODY OF LOOP; AT END, 
LEAVES TRUTH VALUE, N, 
ON TOP OF STACK 



: 




BEGINNING VALUE OF LOOP IS 



"I 



. ON TOP OF STACK; 1 + ENDING 
' VALUE OF LOOP IS NEXT-TO-TOP 



N IS TESTED HERE; 

IF N=0, CONTROL TRANSFERS TO "BEGIN"; 
IF N#0, CONTROL TRANSFERS TO FIRST WORD 
AFTER "UNTIL" 

(a) 



OF STACK 



-J 



J WITHIN BODY OF LOOP, 



FORTH WORD "l" 
B + 2,--- L-l 




BY THIS POINT. 

THE TRUTH VALUE, I 

N, IS ON TOP OF I 

I STACK I 

I I 



Figure 3: An explanation of the DO . . . LOOP construct. As shown in figure 3a, the top 
number on the stack is taken to be the lower limit of the loop variable, I, and the next- 
to-top number on the stack is the upper limit of the loop variable + 1. The body of the 
loop is shaded, and the loop variable is incremented and tested after the body of the 
loop is executed. Figure 3b gives the equivalent construct in conventional flowchart 
notation. 



Figure 4: An explanation of the 
BEGIN ... UNTIL construct. As shown in 
figure 4a, the body of the loop (shaded) is 
repeated only if the value on top of the 
stack when the word UNTIL is reached is 
false. Figure 4b gives the equivalent con- 
struct in conventional flowchart notation. 




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118 August 1980 $ BYTE Publications Inc 



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BYTE August 1980 119 



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Listing 8: An example of FORTH looping. A practical use of FORTH' s structured loop- 
ing is this terminal output handler. This example is for a PDP-11; an example for other 
computers would be similar. Address 177564 (octal) is the output status register of the 
console terminal; bit 7 of this address is set when the device is ready to receive a 
character. The ASCII code for the output character can then be placed in address 
177566 (the data buffer register). 

The FORTH word @ (pronounced fetch) does the work of PEEK in BASIC; it treats 
the number on top of the stack as an address and replaces it with the contents of that ad- 
dress word. AND does a "bitwise" boolean AND operation. So 
{ 177564 @ 200 AND } indicates true (nonzero) only if bit 7 of the status register is 
set. Until then, the BEGIN ... UNTIL loop does a waiting loop ending on the above 
condition. When the device is ready, the argument that was given to TERMINAL-OUT 
(the ASCII character to be written) is still on top of the stack. { ! } (pronounced store) 
stores the word that is second on the stack into the address that is on top of the stack; 
so { 177566 ! } transmits the character to the terminal data buffer register, from 
which it will be written onto the terminal by the hardware of the PDP-11 system. 

The FORTH word ASCII-TEST was written to test the TERMINAL-OUT word. It 
transmits ASCII values for all of the printable character set. 

Listing 9 shows the same device handler, only written in machine-language code with 
a FORTH assembler. 



jCTHL !"K 



; TERHiPL-nu T 


i f 


Hrlp -; 


TERHJNfiL 


Hi 


TPuT hhND 


Fi? 


PDF 


-ii) 


BEGIN 177564 


§ 21 


!l RNB 


UNI I L ; M 


T 


TILL FORT 


RE? 


BY) 




177566 ' I 


TRfir 


SHIT ! 


rlE ^MHKflCTER 




NT CHfiRJiC 


TPP 


S h T ) 




! OK 
: HSCII-TEST 


( - > 


, TEi 


T hRNBtER - 


: R 




17? 4lj ( T 


R H f j S F 


IT HSC 


II BUM THR 


ill! 


iH ! * ! ) 


i } 






BO I TERrtlNH 


L-OU" 


i nop 


i |iiJ T puT ThE 


chhRhcter 





I ijfc 

IECIHHL ok 

HSH 1 1 -TEST >'!$>£: ? w*+!-,' 0123456789; <<- • ? §fl B C D E F Q H I J k l fi ri t • P y R S T J y N 5^ f Z ? " 3i*_ ( fi8CB 

EF5HI,TKLHNGF5RSTLH;NXYl{i}* OK 



Listing 9: FORTH words defined by machine-language subroutines, for PDP-11 and for 
8080 processors. The operation TERMINAL-OUT-2 behaves exactly the same as 
TERMINAL-OUT defined in listing 8, but it is written in assembly language. FORTH 
assemblers use postfix notation, so address-mode symbols and operation codes (instruc- 
tion mnemonics) follow their operands, unlike conventional assemblers. In the PDP-11 
example (listing 9a), { 177564 200 # BIT, } in line 2 assembles a "bit test" instruction 
that does a logical AND between address 177564 and the literal 200 (§ indicates literal), 
setting condition codes. { UNTIL, } assembles a conditional branch back to the cor- 
responding { BEGIN, }. The commas are part of the operation names, not punctua- 
tion. The word NE tells the { UNTIL, } what kind of conditional branch to assemble. 
There are also { IF, }...{ THEN, }and{ IF, }...{ ELSE, }...{ THEN, } operations; 
all these code-level structures can be nested. 

In the 8080 example (listing 9b), the machine-language subroutine sets up a call to the 
character-output routine in the North Star disk operating system. In contrast, the 
PDP-11 example outputs directly to the hardware without using any software outside of 
FORTH. Either approach could be used on either machine, of course, and each has its 
own advantages. 

The word CODE , like { : } (colon, introduced in listing 3), creates a new definition 
in FORTH's dictionary for the word following it. CODE also sets the number base (to 
octal for PDP-11 and to hexadecimal for 8080), saving the original number base, which 
is later restored by { C; }. CODE also changes the vocabulary, which allows the same 
names to have different meanings in the assembler and in the rest of FORTH without 
confusion. Users can create their own vocabularies and subvocabularies to keep dif- 
ferent application libraries separate. 

Many FORTH programmers never need to write machine-language subroutines, so 
they do not need to use an assembler. FORTH assemblers have an unfamiliar postfix 
notation, but they have the advantage of giving immediate feedback. You know right 
away whether an operation works, with no wait for assembly passes, linkitig passes, 
and file handling. This interactive assembly greatly speeds program development and 
allows more thorough testing. 

Listing 9 continued on page 122 



120 August 1980 © BYTE Publications Inc 



WHAT WOULD YOU SAY TO 



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Listing 9 continued: 

Collectively, { : } and CODE are called defining words because they are used to 
create new FORTH words. There are several other such functions in FORTH, and users 
can also define their own types of defining words, creating new data types or operation 
types; see listing 10. 



CCSE TERHINRL-QUT-2 



i.'HHk' 



TERMINAL OUTPUT HANDLER; PBP-ii? 



BEGINi 


17 


"564 200 


i BIT 


NE 


UNTI 


L> 


NHIT TILL 


P\\" 


REPDf ■ 


S )+ 17 


7 5bb 


HOU, ( 


POP 


"ORTH 


3T8CK 


INTO 


BATH REGIS 


r ER i 


bi 


NEXT. 


( a 


2-IflSTRU 


:tion 


rlRCRO 


TO C 


MINI 


E FORTH EX 


^u T I 


ON) OK 



« GET OUT OF THE FORTH ASSEMBLER) OK 



flCTJL OK 



RSCII-TEST-2 



'BINT RSCii C H R R H C T E R SET* 



177 40 ( ASCII BLANK THROUGH '*') 

BO I TERriiNHL-OUT-2 LOOP ( OUTPUT THE CHARACTERS) 
_L OK 
IECIHAL OK 
NSiiI-TEsT-2 s |J«U'*+!-i'Uii3456?B9iK = ;' i ?HECBEFGHiJ«LM^in i il' i !iTijja(S*Z! ■ 



CBEFGHlJKlHStOP8RSTUMNXYZ'{i}* OK 

.■ ,". r. T t rrr.T i c u i. i ,.-.■/ \ - . . .-. j .-. .-v j r— r *t ■■■..-.-■ i r-- J-. ."% IV .-. T* r* r- ."v i : T t i .- 1 lj | t .». r\ ,-. r. ■-. t p r : t 1 < i ij -t r . i .". 

H-l 1 1-Tt^ I I if%8 I )*t< -, ■• "li.ii'h; hS; i \ = f ■^HJSi-l!tHirHi!HnHl,r'b!Kl) : U'JW,- I LI -j 
EFGHI JKLNNOPSRSTUVHXYZtl }* OK 



CONSTANT DEV ( DEVICE NO FOR NORTHSTAR DOS ) OK 

200D CONSTANT COUT ( NORTHSTAR DOS CHAR OUT JUMP POINT ) OK 

CODE TF.RMINAL-OUT-2 ( CHAR->. 8080 WITH NORTHSTAR DOS ) OK 



H POP ( CHARACTER IS ON STACK, POP TO 1IL ) OK 

B PUSH ( BC IS INSTRUCTION POINTER, SAVE IT ) OK 

L B MOV ( DOS EXPECTS CHAR IN B REGISTER ) OK 

DEV A MVI ( AND DEVICE NUMBER IN ACCUMULATOR ) OK 

COUT CALL B POP NEXT JMP C; ( DO ] T AND CONTINUE ) OK 



Listing 10: User-defined data types. Because this example is longer, it was not typed in 
directly like the others, but was stored on disk with an editor (the editor session is not 
shown here). This example is contained in two disk screens, each of which is a virtual 
block of 1024 bytes (see text). The commands { 58 LIST } and { 59 LIST } print these 
screens. The line numbers (0 thru 15) are not part of the program and are used only by 
the editor. 

This example creates table-lookup sine and cosine routines for integer-degree 
arguments. The results are accurate enough for most graphics applications, making this 
situation an example of the versatility of FORTH, even without floating-point routines. 

The definition of TABLE creates a new data type. When TABLE is executed, it creates 
a new table of numbers taken from the stack; the number on top of the stack tells how 
many items there are in the table. In this case, { 91 TABLE SINTABLE } creates a 
table called SINTABLE with ninety-one entries; these entries are the values of the sine of 
0° thru 90°, multiplied by 10,000 so that they can be expressed as integers. SINTABLE 
gives the sine (scaled by 10,000) of 0° thru 90° degrees; SIN does the same, except that 
its argument can be any number of degrees (from —32,768 to 32,767). 

Incidentally, few FORTH programs use as much depth of stack as this one. The 
system used for listings 1 thru 7 limits the stack depth in order to use "page 0" memory 
for speed, so this example would have to be modified to run on it. 

The < BUILDS ... DOES> construct, which creates the new data type, is one of the 
most advanced concepts of FORTH. Briefly, the < BUILDS part is executed when 
SINTABLE is defined; that is, it creates the table. The DOES> part defines what hap- 
pens when SINTABLE is executed. Once TABLE has been defined, any number of 
tables of varying length can be declared using the word. Similar definitions can create 
special-purpose arrays such as word, byte, or bit arrays, user-defined record structures 
or other data objects, or user-defined classes of operations. /An excellent explanation of 
the words < BUILDS and DOES> is given in Kim Harris' article "FORTH 
Extensibility," also in this issue GW/ 



- NITH SINE *10000 MIT) 
CREATE 'TABLE' BATA TYPE,) 
< COMPILE N ELEMENTS) 
( EXECUTE TABLE LOOKUP) 



OK 




58 L 




SCR t 


58 


i) 


TRIG LOOKUP ROUTINES 


1 


TABLE ( ... N -) . 


2 


(BUILDS BO ■ LOOP 


3 


BOES) SWAP 2 * + 3 


4 


I 



Listing 10 continued on page 124 



122 August 1980 © BYTE Publications Inc 



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• Plastic cover. 

Three comprehensive manuals: 

• Instruction Manual— 20 video game 
listings, schematics, much more. 

• User's Guide— operating instructions 
and CHIP-8 for the beginner. 

• RCA 1 802 User's Manual (MPM- 

201 B)— complete 1 802 reference guide. 

RC/1 



Add computer power a 
board at a time. 

With easy-to-buy options, the versatile 
RCA hobby computer means even 
more excitement. More challenges in 
graphics, games and control functions. 
For everyone, from youngster to serious 
hobbyist. 

Built around an RCA COSMAC micro- 
processor, our hobby computer is easy 
to program and operate. Powerful 
CHIP-8 interpretive language gets you 
into programming the first evening. 
Complete documentation provided. 

Send the coupon now... 

Complete the coupon below and mail to: 
RCA Microcomputer Customer Service, 
New Holland Ave., Lancaster, PA 1 7604. 

Or call toll free (800) 233-0094 

to place your Master Charge or VISA 
credit card order. In Pennsylvania, 
call (71 7) 397-7661 , extension 31 79. 



Please send me the items indicated. 

□ VP-111 New low cost Microcomputer 

(See description above) $ 99 

D VP-114 Expansion Kit for VP-111— Includes 

3K RAM, I/O Port and connectors $ 76 

□ VP-711 The original VIP Microcomputer 

(See description above) $199 

□ VP-44 RAM On-Board Expansion Kit— Four 

21 1 4 RAM ICs. Expands VP-71 1 

memory to 4K Bytes 

D VP-590 Color Board— Adds color. Four 
background and eight 
foreground colors 

□ VP-595 Simple Sound Board— Provides 

256 programmable frequencies. For 
simple music or sound effects. 
Includes speaker $ 

□ VP-550 Super Sound Board— Turns 

VP-1 1 1 /71 1 into a music synthesizer 
Two independent sound channels. 
Outputs to audio $ 

D VP-551 4-Channel Super Sound— Includes 
VP-576 and demo cassette. Requires 
VP-550 and 4K RAM $ 

D VP-570 Memory Expansion Board— 

Plug-in 4K RAM memory $ 

□ VP-580 Auxiliary Keypad— Adds two-player 

interactive capability. Connects 

to VP-590 or VP-585 $ 

D VP-585 Keypad Interface Board— Interfaces 
two VP-580 Auxiliary Keypads 
toVP-111/711 $ 

□ VP-560 EPROM Board— Interfaces two 

271 6 EPROMS to VP-1 11/711 .. $ 



$ 36 



$ 69 



30 



49 



74 



□ VP-565 EPROM Programmer Board- 

Programs 2716 EPROMs. 

With software $ 99 

□ VP-575 Expansion Board— Provides 4 

buffered and one unbuffered 

expansion sockets $ 59 

□ VP-576 Two-Board Expander— Allows 

use of 2 Accessory Boards in either 
I/O or Expansion Socket $ 

□ VP-700 Tiny BASIC ROM Board-BASIC 

code stored in 4K of ROM $ 

□ VP-701 Floating point BASIC for 

VP-71 1 on cassette. Requires 1 6K 
Bytes RAM (avail. 7/80) $ 49 

□ VP-710 Game Manual— Listing for 16 

exciting games $10 

D VP-720 Game Manual-ll— More games . . $ 15 



20 



39 



ASCII keyboards. 

□ VP-601 Keyboard— 128-character ASCII 

encoded alphanumeric 8-bit parallel 
output $ 69 

D VP-606 Keyboard— Same as VP-601. 

Asynchronous serial output $ 99 

□ VP-611 Keyboard— Same as VP-601 plus 

16-key numeric keypad $ 89 

□ VP-616 Keyboard— Same as VP-606 plus 

16-key numeric keypad $119 

□ VP-620 Cable— Connects VP-601 /611 to 

VP-1 11/711 $ 20 

□ VP-623 Cable— Unterminated for 

VP-601 /611 $ 20 

D VP-626 Conneclor— Male "O" mates to 

VP-606/616 $ 7 



Enclosed is $ for items checked plus shipping & handling charge of $3.00. 

Add your state and local taxes $ Total enclosed $ 

I enclose □ check or D money order. Or charge my □ VISA □ Master Charge. 
Credit card account No. 



95 Master Charge Interbank No. 



Expiration date . 



20 



15 



Signature (required for credit orders): 

Name (please type or print): 

Street address: 

State & Zip: 



. Telephone:! 



.City:. 



34 Make checks payable to RCA Corp. Prices and specifications are subject to change without notice. 



Circle 80 on inquiry card. 



BYTE August 1980 123 



•Iv PERSONAL 
ATARI* COMPUTER 



A Warner Communicalic 
Company ^W 



SYSTEMS 



ATARI® 800™ 
List $1080 

ONLY $849 




ATARI® 400™, List $630 
OUR PRICE ONLY $499 

820 PRINTER, List $599.95 $499 

810 DISK DRIVE, List $699.95 $589 




HP-85 

Call for Price 



• Extended BASIC Language 

• Advance Graphics 

• CRT Built-in Display 

• Magnetic Tape Cartridge for Storage 



CALCULATORS BY 



HEWLETT 



M 



PACKARD 



HP-41C Calculator, "A System" . . .$289.95 
HP-32E Scientific w/Statistics ... $ 53.95 
HP-33C Scientific Programmable . . . 99.95 
HP-34C Advanced Scientific 

Programmable 123.95 

HP-37E Business Calculator 58.95 

HP-67 Handheld Fully Advanced 

Programmable Scientific for 

Business & Engineering 298.95 

HP-97 Desktop w/ Built-in Printer . . 579.95 



APPLE II, 16K, List $1195 $ 989 

32K, List $1395 $1169 

48K 1259 

COMMODORE PET Call for Prices 

Prices do not include shipping by UPS. All 
prices and offers are subject to change without 
notice. 



R 



ersonal 
omputer 
ystems 



C 



S 



609 Butternut Street 

Syracuse, N.Y. 13208 

(315) 478-6800 



Listing 10 continued 



5 


10000 9998 9994 9986 9976 9962 9945 9925 


6 


9848 9816 9781 9744 9703 9659 9613 9563 


1 


9397 9336 9272 9205 9135 9063 8988 8910 


8 


8660 8572 8480 8387 8290 8192 8090 7986 


9 


7660 7547 7431 7314 7193 7071 6947 6820 


10 


6428 6293 6157 6018 5878 5736 5592 5446 


li 


5000 4848 4695 4540 4384 4226 4067 3907 


12 


3420 3256 3090 2924 2756 2588 2419 2250 


13 


1736 1564 1392 1219 1045 0872 0698 0523 


14 


0000 ( 91 ELEMENTS OF TABLE PLACED 


15 
OK 


91 TABLE SINTABLE ( RETURNS SINE. 0-90 



9903 9877 
9511 9455 
8829 8746 
7880 7771 
6691 6561 
5299 5150 
3746 3584 
2079 1903 
0349 0175 
ON STACK) 
DEGREES ONLY) 



:r j 59 



3 
4 
5 
6 
7 
8 
9 

10 
11 
12 
13 
14 
15 
OK 



SINE AND COSINE TABLE-LOQPUP ROUTINES) 

S180 ( N -> N . RETURNS SINE- 0-180 DEGREES) 

DUP 90 > ( IF GREATER THAN 90 DEGREES! ) 

IF iSO SNAP - ENDIF (SUBTRACT FR0H 180) 

SINTABLE ( THEN TAKE SINE) 

J 

SIN ( N -> SINE. RETURN SINE OF ANY NUHBER OF DEGREES) 
360 HOD ( BRING WITHIN + OR - 360) 
DUP 0< IF 360 + ENDIF ( IF NEGflTIUE- ADD 360) 
DUP 180 ) ( TEST IF GREATER THAN 180) 
IF 180 - S180 MINUS ( IF SO- SUBTRACT 180. NEGATE SINE) 
ELSE S180 ENDIF ( OTHERWISE! STRAIGHTFORWARD) 

COS ( I -> COSINE.) 

360 HOB ( PREUENT OVERFLOW NEAR 32.767) 
90 * SIN ! ( COSINE IS SINE WITH 90 DEGREES PHASE SHIFT) 



OK 

58 LORD 59 LOAD 
I SIN . OK 



OK 



ills 



_ 10000 OK 
30 SIN . 10000 Of 
45 SIN ■ 7071 OK 
1 SIN ■ 175 OK 
61 SIN ■ 175 OK 
060 SIN ■ -9848 
0000 SIN ■ -9848 
0000 COS ■ 1736 
-25281 COS . 1564 
32767 SIN 



OK 

OK 
OK 

OK 
OK 
OK 



1219 

US ■ 9925 

OK 

N DEGREES 



-1 SIN 



-175 



SINSCALE 



N 



SCRL 



SINE) 



SIN 10009 */ ( riULHPtY. THEN BiUIEEJ 32 BITS INTERMEDIATE) 



_L OK 

100 45 SINSCALE , 70 OK 

10000 45 SINSCALE ■ 7071 OK 

30000 -5 SINSCALE ■ -2616 OK 



Circle 81 on inquiry card. 




By Natronics 

ASCII/BAUDOT, 
STAND ALONE 



Computer Sgr 
Terminal 1W 

The Netronics ASCII/BAUDOT Computer Terminal Kit is a 
microprocessor-controlled, stand alone keyboard/terminal 
requring no computer memory or software. It allows the use of 
either a 64, or 32 character by 16 line professional display for- 
mat with selectable baud rate, RS232-C or 20 ma. output, full 
cursor control and 75 ohm composite video output. 

The keyboard follows the standard typewriter configuration 
and generates the entire 128 character ASCII upper/lower case 
set with 96 printable characters. Features include onboard 
regulators, selectable parity, shift lock key, alpha lock jumper, 
a drive capability of one TTY load, and the ability to mate 
directly with almost any computer, including the new Ex- 
plorer/85 and ELF products by Netronics. 

The Computer Terminal requires no I/O mapping and 
includes Ik of memory, character generator, 2 key rollover, 
processor controlled cursor control, parallel ASCII/BAUDOT 
to serial conversion and serial to video processing — fully 
crystal controlled for superb accuracy. PC boards are the 
highest quality glass epoxy for the ultimate in reliability and 
long life. 

VIDEO DISPLAY SPECIFICATIONS 

The heart of the Netronics Computer Terminal is the micro- 
processor-controlled Netronics Video Display Board (VID) 
which allows the terminal to utilize either a parallel ASCII or 
BAUDOT signal source. The VID converts the parallel data to 
serial data which is then formatted to either RS232-C or 20 ma. 
current loop output, which can be connected to the serial I/O 
on your computer or other interface, i;e., Modem. 

When connected to a computer, the computer must echo the 
character received. This data is received by the VID which 
processes the information, converting to data to video suitable 
to be displayed on a TV se't "(using an RF modulator) or on a 
video monitor. The VID generates the cursor, horizontal and 
vertical sync pulses and performs the housekeeping relative to 
which character and where it is to be displayed on the screen. 
Video Oulput: 1.5 P/P into 75 ohm (EIA RS-170) • Baud Rate: 
110 and 300 ASCII • Outputs: RS232-C or 20 ma. current loop 
* ASCII Character Set: 128 printable characters— 



!"m4 , ()*+,-./0123456789: ;<=>? 
WBC0EFWIJKUtCP«c3TUUyXVZt\] A . 

x abcdef9KijklAnowrstuvwxyz-C'iHI 



BAUDOT Character Set: A BCDEFGHIJKLMNOPQ 
RSTUVWXYZ-?:*3$#().,9014!57;2/68* 
Cursor Modes: Home, Backspace, Horizontal Tab, Line Feed, 
Vertical Tab, Carriage Return. Two special cursor sequences 
are provided for absolute and relative X-Y cursor addressing • 
Cursor Control: Erase, End of Line, Erase of Screen, Form 
Feed, Delete • Monitor Operation: 50 or 60Hz fjumpei 
selectable. 

Continental U.S.A. Credit Card Buyers Outside Connecticut 

CALL TOLL FREE 800-243-7428 

To Order From Connecticut Or For Technical _ , __ 
IT Assistance, Etc. Call (203)354-9375 

I Netronics R&D Ltd., Dept. B-8 
333 Litchfield Road, New Milford, CT 06776 

I Please send the items checked below — 

ID Netronics Stand Alone ASCII Keyboard /Computer 
Terminal Kit, $149.95 plus $3.00 postage & handling. 
ID Deluxe Steel Cabinet for Netronics Keyboard/Termi- 
nal In Blue/Black Finish, $19.95 plus $2.50 postage 
I and handling. 
D Video Display Board Kit alone (less keyboard), $89.95 

I plus $3 postage & handling. 
D 12" Video Monitor (10 MHz bandwidth) fully assem- 
Ibled and tested, $139.95 plus $5 postage and handling. 
D RF Modulator Kit (to use your TV set for a monitor), 

I $8.95 postpaid. 
D 5 amp Power Supply Kit In Deluxe Steel Cabinet 
I(±8VDC @ 5 amps, plus 6-8 VAC), $39.95 plus $2 
postage & handling. 
I Total Enclosed (Conn. res. add sales tax) $ 
By- 

ID Personal Check □ Cashiers Check/Money Order 
D Visa D Master Charge (Bank #_ ) 

I Acct. tt . 



- Signature. 

I Print 

■ Name 



_Exp. Date . 



I 



City. 



„ Zip 



D Send Me More Information i^ m t ^ m J 



Start Computing For Just $129.95 With An 
8085-Based Professional Computer Kit— 

Explorer/85 

100% compatible with all 8080A and 
8085 software & development tools! 

No matter what your future computing plans may 
be, Level "A " — at $129.95 — is your starting point. 

Starting at just $129.95 for a Level "A " operating system, 
you can now build the exact computer you want. Explorer/85 
can be your beginner's system, OEM controller, or IBM- 
formatted 8" disk small business system. . .yet you're never 
forced to spend a penny for a component or feature you don t 
want and you can expand in small, affordable steps! 

Now, for just $129.95, you can own the first level of a fully 
expandable computer with professional capabilities — a com- 
puter which features the advanced Intel 8085 cpu, thereby 
giving you immediate access to all software and development 
tools that exist for both (he 8085 and its 8080A predecessor 
(they are 100% software compatible) — a computer which 
features onboard S-100 bus expansion — plus instant conver- 
sion to mass storage disk memory with either 5-1/4" diskettes 
or standard IBM-formatted 8" disks. 

For just $129.95 (plus the cost of a power supply, keyboard/ 
terminal and RF modulator, if you don't have them already), 
Explorer/85 lets you begin computing on a significant level. . . 
applying the principles discussed in leading computer maga- 
zines. . .developing "state of the art" computer solutions for 
both the industrial and leisure environment. 
Level "A" Specifications 

Explorer/85's Level "A" system features the advanced Intel 
8085 cpu, an 8355 ROM with 2k deluxe monitor/operating 
system, and an 8155 ROM-I/O — all on a single motherboard 
with room for RAM/ROM/PROM/EPROM and S-100 ex- 
pansion, plus generous prototyping space. 

(Level "A" makes a perfect OEM controller for industrial 
applications and is available in a special Hex Version which 
can be programmed using 
the Netronics Hex Keypad/ 
Display.) 

PC Board: glass epoxy, plated 
through holes with solder mask 
• I/O: provisions for 25-pin 
(DB25) connector for terminal 
serial I/O, which can also sup- 
port a paper tape reader 
. . . provision for 24-pin DIP 
socket for hex keyboard/dis- 
play. . .cassette tape recorder in- 
put. . .cassette tape recorder output. . .cassette tape control 
output. . .speaker output... LED output indicator on SOD 
(serial output) line. . .printer interface (less drivers). . .total of 
four 8-bit plus one 6-bit I/O porls»Crystal Frequency: 6.144 
MHz • Control Switches: reset and user (RST 7.5) 
interrupt. . .additional provisions for RST 5.5, 6.5 and TRAP 
interrupts onboard • Counter/Timer: programmable, 14-bit 
binary • System RAM: 256 bytes located at F800, ideal for 
smaller systems and for use as an isolated stack area in 
expanded systems. . .RAM expandable to 64k via S-100 bus or 
4K on motherboard. 

System Monitor (Terminal Version): 2k bytes of deluxe 
system monitor ROM located at F000 leaving 0000 free for user 
RAM/ROM. Features include tape load with labeling . . .tape 
dump with labeling. . .examine/change contents of memory 
. . .insert data. . .warm start. . .examine and change all 
registers. . .single step with register display at each break point, 
a debugging/training feature... go to execution address... 
move blocks of memory from one location to another. . .fill 
blocks of memory with a constant . . .display blocks of memory 
. . . automatic baud rate selection . . . variable display line length 
control (1-255 characters/line). . .channelized I/O monitor 
routine with 8-bit parallel output for high speed printer. . . 
serial console in and console out channel so thai monitor can 
communicate with I/O ports. 

System Monitor (Hex Version): Tape load with labeling. . . 
tape dump with labeling. . .examine/change contents of mem- 
ory... insert data... warm start .. .examine and change all 

J Netronics R&D UoT, Bep™ ™ ^ ^ ™" mm 
I 333 Litchfield Road. New Milford, CT 06676 

■ Please send the items checked below — plus $2 p&h. 



By Netronics 




Level "A" at $129.95 is a 
complete operating system, 
perfect for beginners, hob- 
biests, or industrial con- 
troller use. 





Hex Keypad/Display. 




Explorer/85 with 
"C'cardcage. 



□ Explorer/85 Level "A" Kit (ASCII 
Version), $129.95 plus $3 p&h. 

D Explorer/85 Level "A" Kit (Hex 

Version), $129.95 plus $3 p&h. 

D 8k Microsoft BASIC on cassette 

tape, $64.95 postpaid. 

D 8k Microsoft BASIC in ROM Kit 

(requires Levels "B," "D," and "E"), 

$99.95 plus $2 p&h. 

□ Level "B" (S-100) Kit, $49.95 plus 
$2 p&h. 

□ Level "C" (S-100 6-card expander) 
Kit, $39.95 plus $2 p&h. 

D Level "D" (4k RAM) Kit, $69.95 
plus $2 p&h. 

□ Level "E" (EPROM/ROM) Kit, 
$5.95 plus 5(K p&h. 

D Deluxe Steel Cabinet for Explorer/ 
85, $49.95 plus $3 p&h. 

□ ASCII Keyboard/Computer Ter- 
minal Kit (features a full 128 character 
set, upper & lower case, full cursor con- 

Itrol, 75 ohm video output convertible 
to baudot output, selectable baud rate, 
IRS232-C or 20 ma. I/O, 32 or 64 char- 
acter by 16 line formats, and can be 
I used with either a CRT monitor or a TV 
set (if you have an RF modulator), 
m $149.95 plus $2.50 p&h. 
I D Hex Keypad/Display Kit. $69.95 

k HM HM MM !1M HI ■■■ KJIII 



registers. . .single step with register display at each break point 
...go to execution address. Level "A" in the Hex Version 
makes a perfect controller for industrial applications and can 
be programmed using the Netronics Hex Keypad/Display. 
Hex Keypad/Display 
Specifications 

Calculator type keypad with 24 
system defined and 1 6 user 
defined keys. 6 digit calculator 
type display which displays full 
address plus data as well as 
register and status information. 

Level "B" Specifications 

Level"B" provides the S-100 signals plus buffers/drivers to 
support up to six S-100 bus boards and includes: address 
decoding for onboard 4k RAM expansion select-able in 
4k blocks. . .address decoding for onboard 8k EPROM expan- 
sion selectable in 8k blocks. . .address and data bus drivers for 
onboard expansion. . .wait state generator (jumper selectable), 
to allow the use of slower memories. . .two separate 5 volt 
regulators. 

Level "C" Specifications 

Level "C" expands Explorer's 
motherboard with a card cage, 
allowing you to plug up to six 
S-100 cards directly into the 
motherboard. Both cage and 
*-"' cards are neatly contained inside 
Explorer's deluxe steel cabinet. 
Level "C" includes a sheet metal superstructure, a 5-card gold 
plated S-100 extension PC board which plugs into the mother- 
board. Just add required number of S-100 connectors 

Level "D" Specifications 

Level "D" provides 4k or RAM, power supply regulation, 
filtering decoupling components and sockets to expand your 
Explorer/85 memory to 4k (plus the original 256 bytes located 
in the 8155A). The static RAM can be located anywhere from 
0000 to EFFF in 4k blocks. 
Level "E" Specifications 

Level "E" adds sockets for 8k of EPROM to use the popular 
Intel 2716 or the Tl 2516. It includes all sockets, power supply 
regulator, heat sink, filtering and decoupling components. 
Sockets may also be used for soon to be available RAM IC's 
(allowing for up to 12k of onboard RAM). 

Order A Coordinated 
Explorer/65 Applications Pak! 

Experimenter's Pak (SAVE $12.50)— Buy Level "A" and Hex 
Keypad/Display for $199.90 and get FREE Intel 8085 user's 
manual plus FREE postage & handling! 
Student Pak (SAVE $24.45)— Buy Level "A," ASCII Key- 
board/Computer Terminal, and Power Supply for $319.85 and 
get FREE RF Modulator plus FREE Intel 8085 user's manual 
plus FREE postage & handling! 

Engineering Pak (SAVE $41.00)— Buy Levels "A," "B," 
"C," "D," and "E" with Power Supply, ASCII Keyboard/ 
Computer Terminal, and six S-100 Bus Connectors for $514.75 
and get 10 FREE computer grade cassette tapes plus FREE 
8085 user's manual plus FREE postage & handling! 
Business Pak (SAVE $89.95)— Buy Explorer/85 Levels "A," 
"B," and "C" (with cabinet), Power Supply, ASCII Key- 
board/Computer Terminal (with cabinet), 16k RAM, 12" 
Video Monitor, North Star 5-1/4" Disk Drive (includes North 
Star BASIC) with power supply and cabinet, all for just 
$1599.40 and get 10 FREE 5-1/4" minidiskettes ($49.95 value) 
plus FREE 8085 user's manual plus FREE postage & handling! 

Continental U.S.A. Credit Card Buyers Outside Connecticut 

CALL TOLL FREE 800-243-7428 

To Order From Connecticut Or For Technical 

Assistance, Etc. Call (203) 354-9375 ™" "1 

sonalized disk operating system — just| 
plug it in and you're up and running!),! 
$699.95 plus $5 p&h. 
DPower Supply Kit for North Star! 
Disk Drive, $39.95 plus $2 p&h. 

□ Deluxe Case for North Star Disk! 
Drive, $39.95 plus $2 p&h. 

□ Experimenter's Pak (see above),! 
$199.90 postpaid. 

D Student Pak (see above), $319.85 1 
postpaid. 

G Engineering Pak (see above), I 
$514.75 postpaid. 

O Business Pak (see above), $1599.40 1 
postpaid. 



□ Deluxe Steel Cabinet for ASCII 
Keyboard/Terminal, $19.95 plus $2.50 
p&h. 

D Power Supply Kit (± 8V @ 5 amps) 
in deluxe steel cabinet, $39.95 plus $2 
p&h. 

D Gold Plated S-100 Bus Connectors, 
$4.85 each, postpaid. 

□ RF Modulator Kit (allows you to 
use your TV set as a monitor), $8.95 
postpaid. 

□ 16k RAM Kit (S-100 Board expands 
to 64k), $199.95 plus $2 p&h. 

□ 32k RAM Kit, $329.95 plus $2 p&h. 

□ 48K RAM Kit, $459.95 plus $2 p&h. 

□ 64kRAMKit,«89.95pIus$2p&h. 
D 16k RAM Expansion Kit (to expand 
any of the above up to 64k), $139.95 
plus $2 p&h each. 

D Intel 8085 cpu User's Manual, $7.50 

postpaid. 

D Special Computer Grade Cassette 

Tapes, $1.90 each or 3 for $5, postpaid. 

□ 12" Video Monitor (10 MHz band- 
width), $139.95 plus $5 p&h. 

D North Star Double Density Floppy 
Disk Kit (One Drive) for Explorer/ 
85 (includes 3 drive S-100 controller, 
DOS, and extended BASIC with per- 



Total Enclosed $ I 

(Conn. res. add sales tax) By — | 

P Personal Check D M.O./Cashier's | 
Check □ Visa D Master Charge ■ 



(Bank*. 



->' 



Signature 
Print 




Exp. Date 




City 


State 


7ip 





Circle 82 on inquiry card. 



Circle 83 on inquiry card. 



D Send Mc Information ■■ ■ 

BYTE August 1980 125 



SERIES OF STATEMENTS 
THAT LEAVE A TRUTH 
VALUE, N, ON TOP OF STACK- 

I 

| BEGIN A 8 

I 

I WHILE D E 

j_REPEAT 

N IS TESTED HERE; 
IF N=0,JUMPTO FIRST 
WORD AFTER "REPEAT" 



I 

■BODY OF LOOP: 
EXECUTED IF AND ONLY 
IF N# 



(a) 



Figure 5: An explanation of the 
BEGIN . . . WHILE . . . REPEA T construct. 
As shown in figure 5a, the FORTH words 
between BEGIN and WHILE perform 
operations that leave a truth value, N, on 
top of the stack. The value of N deter- 
mines whether the body of the loop (the 
words between WHILE and REPEAT) is 
performed or not. The loop repeats until 
N evaluates to false (N—0). Figure 5b 
gives the equivalent construct in conven- 
tional flowchart notation. 




SELECTED BIBLIOGRAPHY 



I. Bartoldi, P, "Stepwise Development and Acta Press, Anaheim CA, 1976, pp 1 17-122. 



Debugging Using a Small Well-Structured In- 
teractive Language lor Data Acquisition and 
Instrument Control," Proceedings of the In- 
ternational Symposium and Course on Mini- 
and Microcomputers and their Applications, 



2. Ewing, M S, The Caltech FORTH Manual, 
California Institute of Technology, Pasadena 
CA, 1978. 

3. Forsley, L, URTH Tutorial, University of 
Rochester, Rochester NY. 



4. Hicks, S M, "FORTH's Forte is Tighter 
Programming," Electronics, March 15, I979, 
pages 1 14 thru 1 18. 

5. James, J S, "FORTH for Micro 
computers," Dr Dobb's Journal of Computer 
Calisthenics & Orthodontia, May 1978; 
reprinted in SIGPLAN Notices (Special In- 
terest Group on Programming Languages of 
the Association for Computing Machinery), 
October 1978. 

6. Meinzer, K, "IPS, an Unorthodox High- 
Level Language," BYTE, January 1979, 
pages 146 thru 159. 

7. Moore, C H, "FORTH: a New Way to Pro- 
gram a Computer," Astronomy and 
Astrophysics Supplement, 1974, number 15, 
pages 497 thru 51 1. 

8. Moore, C H, and E D Rather, "The FORTH 
Program for Spectral Line Observing," Pro- 
ceedings of the IEEE, September 1973, 
pages 1346 thru 1349. 

9. Rather, E D, and L Brady, Using FORTH 
(2nd rev ed) FORTH Inc, Hermosa Beach CA, 
1980. 

10. Rather, E D, and C H Moore, "The 
FORTH Approach to Operating Systems," 
ACM 1976 Proceedings, Association for Com- 
puting Machinery, 1976. 

11. Sachs, J, An Introduction to STOIC, 
Technical Report BMEC TR001, Harvard-MIT 
Program in Health Sciences and Technology, 
Cambridge MA, June 1976. 

12. Stein, P, "The FORTH Dimension: Mini 
Language Has Many Faces," Computer Deci- 
sions, November 1975, page 10. 

13. Stevens, WR,/( FORTH Primer, Kitt Peak 
National Observatory, Tucson AZ, 1979. 

14. Taylor, A, "FORTH Becoming Hothouse 
for Developing Languages," Computerworld, 
July 30, 1979. 

15. Taylor, A, "FORTH Setting Coding 
Trend?," Computerworld, August 13, 1979. 

16. Taylor, A, "Trade Language Families Can 
Sprout from FORTH," Computerworld, 
August 27, 1979. 

17. Wells, D C, "Interactive Image Analysis 
for Astronomers," Computer, August 1977, 
pages 30 thru 34. 



f S-1 OO USERS: GIVE YOUR COMPUTER THE GIFT OF SIGHT! 



The DS-80 Digisector® is a random 
access video digitizer. It works in 
conjunction with a TV camera (either 
interlaced or non-interlaced video) and 
any S-100 computer conforming to the 
IEEE standards. Use it for: 

• Precision Security Systems 

• Moving Target Indicators 

• Computer Portraiture 

• Fast To Slow Scan Conversion 

• Robotics 

• Reading UPC Codes, schematics, 
paper tape, musical scores 




CHECK THESE FEATURES: 

□ High resolution — a 256 x 256 pic- 
ture element scan 

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Text continued from page 10: 

You should also look at FORTH if 
you have limited computer or finan- 
cial resources. FORTH is a big 
language in a small package, and you 
can buy a version of FORTH for as 
little as $20. (See "Selected FORTH 
Vendors," on page 98.) Unlike most 
new languages that gobble up more 
and more of the 64 K bytes allotted to 
an 8-bit microcomputer (some won't 
comfortably fit in 64 K bytes), there is 
plenty of room for very large FORTH 
programs even in a 16 K machine. 
FORTH takes up only about 8 K 
bytes, and this can be pared down; in 
an industrial application that will run 
only one program, the FORTH inter- 
preter can be made as small as 800 
bytes. Also, FORTH can be run on 
cassette-based systems due to its 
small size; although this is still more 
inconvenient than running FORTH 
on a disk system, most languages that 
use a disk are impractical or impos- 
sible on cassette-only systems. 

Finally, you may want to consider 
FORTH for applications where speed 
is of the utmost importance. Since 
portions (or all) of a FORTH program 
can be written in the assembly lan- 



guage of the host computer, FORTH 
programs can be written that com- 
pare favorably in speed with 
machine-language programs. And, 
again, productivity is higher using 
FORTH than it is with machine 
language. 

What Is a Threaded Language? 

Imagine a language that starts with 
a few fundamental subroutines writ- 
ten in the machine language of the 
host computer; eg: routines to put a 
character to the display device, to get 
a character from the keyboard, to 
multipy two fixed-point numbers. 
Then imagine that the only way to 
combine these subroutines is to string 
them together (with embedded data 
bytes) as a series of subroutine calls; 
eg: a routine to get a signed multidigit 
number from the keyboard is written 
as a controlled series of calls to the 
subroutine that gets a character. Then 
these routines are called by other 
routines that perform even bigger 
tasks. For example, a routine to sum a 
series of signed numbers entered from 
the keyboard is written as series of 
subroutine calls that includes the one 
mentioned just above. The final pro- 



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Special Notation Used in 
This Issue 

Because FORTH is such an 
unusual language (it uses punctua- 
tion marks by themselves and 
within words), a pair of braces, 
{ } , is sometimes used to set 
apart FORTH words from the rest 
of the text. Braces are used under 
the following conditions: 

• When the material being 
quoted is a series of FORTH 
words; eg: { 26 LOAD } ; 

• When the FORTH word is or 
contains any of the following 
punctuation marks: period, 
comma, colon, question 
mark, exclamation point, 
single quote mark, or double 
quote mark. Two examples 
are { . } and { (") }. 

In addition, spaces are always 
used to separate FORTH words 
from other words or punctua- 
tion — even when this means doing 
something like "...the words 
BEGIN , WHILE , and REPEAT 
are all. . . " (spaces between FORTH 
words and the commas that follow 
them). There are two reasons for 
doing this: first, for clarity; and se- 
cond, to emphasize that the 
FORTH word in question does not 
include the punctuation that 
follows. Some FORTH words do 
contain punctuation (eg: { IF, }), 
but such words will always be 
enclosed in braces (except within 
program listings). 



gram in such a threaded language is a 
series of calls to lower and lower 
subroutines, dipping repeatedly into 
machine-language routines under the 
control of higher-level routines. The 
addresses in each subroutine that 
point to the subroutine or machine 
language under it make up a "thread" 
of control that runs through the entire 
program. 

FORTH has so far been im- 
plemented as a threaded language. 
Threadedness is a language im- 
plementation technique, not an in- 
herent quality of any language; 
SNOBOL and FORTRAN compilers 
have been written using threaded 
code. 



128 August 1980 © BYTE Publications Inc 



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BYTE August 1980 



129 



FORTH: Pro and Con 

Pros: I have already mentioned 
most of the advantages of FORTH. 
The language is: 

• Compact; 

• Fast, although this is due to its 
implementation in threaded 
code, not its inherent qualities; 

• Structured: it has the major 
constructs of structured pro- 
gramming and, in fact, does 
not have any kind of goto 
statement, thus forcing it to be 
structured; 

• Extensible; 

• Highly portable. 

These last two features deserve fur- 
ther description. The extensibility of 
FORTH is probably its most impor- 
tant feature. Never before in a high- 
level language has it been so easy to 
add new features, new data types, 
and new operators to a language. 
Unlike other languages, these new 
words (everything in FORTH is called 
a word) have the same priority and 
receive the same treatment as words 
defined in the standard FORTH 
vocabulary. For example, you can 



define a word 10+ that will add ten 
to any number it is given; or, in fact, 
you can even redefine the addition 
operator + . You can also define en- 
tirely new families of words in 
FORTH. This advanced topic is ably 
discussed in what I believe is the only 
written treatment of the subject 
anywhere in FORTH literature by 
Kim Harris in his article, "FORTH 
Extensibility," on page 164. 

Most FORTH programs can be 
transferred from, say, a mainframe 
computer to a microcomputer 
without modification; therefore, 
FORTH is highly portable. Most of 
the FORTH words supplied in a given 
system have been defined to do the 
same operation regardless of the com- 
puter used. Although the vocabulary 
of words varies from supplier to sup- 
plier, most FORTH programs will run 
with minor or no modifications. A 
standard set of words, called 
FORTH-79, collectively developed by 
many of the major suppliers and users 
of FORTH, will help in this situation. 

Cons: Here are some of the disad- 
vantages of FORTH: 

• FORTH code is hard to read. 



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This is probably the most common 
complaint against the language. As a 
new user, I can say that you slowly 
get used to the odd syntax of the 
language. The stack architecture (see 
below) of the language contributes to 
the novice's initial disorientation, but 
this feeling is usually blamed on the 
unreadability of the language. In ad- 
dition, the stack architecture en- 
courages the storage of working 
values on the stack rather than in 
variables with names. Variable 
names, if chosen properly, give vital 
clues to the workings of a program; 
this scarcity of variable names makes 
most FORTH programs less readable. 
Adequate indentation and comments 
can help a FORTH program, but pro- 
grammers of FORTH, like program- 
mers of all other languages, often 
omit these aids to comprehension. 

• The stack architecture of 
FORTH offers disadvantages as well 
as advantages. Remember the odd 
feeling you got the first time you used 
a Hewlett-Packard calculator and had 
to punch in " 5 ENTER 3 + " instead 
of the more understandable "5 + 3 
= " ? FORTH uses the same reverse 
Polish notation (abbreviated RPN), 
where the objects being entered come 
before the operators that work on 
them. 

Not only does this take some get- 
ting used to (it takes even longer 
before you can fluently "think in 
FORTH"), it also encourages a scar- 
city of named variables, as mentioned 
above. In addition, stack-manipu- 
lating words like SWAP, DUP (for 
duplicating the top entry on the 
stack), ROT (for rotating the top 
three items on the stack), and others 
muddle the FORTH program and 
make it hard to tell just what variable 
is being operated on. This uncertainty 
is particularly evident during debug- 
ging; most of your time is spent find- 
ing out why what you thought was 
on the stack isn't there. 

• FORTH encourages program- 
ming "tricks" in place of plain, easier 
to read programming. Although the 
examples to support this statement 
have already been mentioned, I think 
the statement as a generality is true. 
We must remember that, especially 
since lack of memory is usually not a 
problem in FORTH, FORTH pro- 
grammers should name appropriate 
variables and, in general, worry less 
about fitting a program on one screen 
(a basic unit of FORTH program- 



130 August 1980 © BYTE Publications Inc 



Circle 88 on inquiry card. 



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BYTE August 1980 131 



ming) and more about making it 
readable. 

However, drawing a comparison to 
APL, any language that compresses a 
lot of program into a small number of 
lines suffers from readability prob- 
lems. Broad, powerful algorithms 
often represent complex processes; 
when they are described in a terse 
notation, they look like programming 
tricks. In this case, the only remedy is 
to use a lot of comments. The lack of 
such comments is solely the fault of 
the programmer, not of the computer 
language. 

• FORTH lacks many of the 
programming constructs we are used 
to — strings, arrays, floating-point 
numbers — but that's not the whole 
story. Many applications, for exam- 
ple, can get by without floating-point 
numbers: look at the number of pro- 
grams written in Integer BASIC for 
the Apple II. With a maximum ab- 
solute numeric value of 32,767, nor- 
mal FORTH can handle many prob- 
lems by simply assuming a decimal 
point. In addition, all versions of 
FORTH can add all these features and 
more, simply by defining new words. 
For example, MMSFORTH, a version 



of FORTH for the TRS-80 by Miller 
Microcomputer Services, has over ten 
screens (each screen is 16 lines of 
source code) that implement their 
version of words for double-precision 
math, arrays, strings, random 
numbers, and TRS-80 graphics. You 
compile a series of screens, thus add- 
ing to the size of your resident 
FORTH interpreter, only if you need 
these features. So you can have all 
these programming constructs and 
tools, but only if you write them 
yourself or get somebody else to write 
them for you. 

Friends of FORTH 

Almost everyone who is working 
in FORTH professionally is doing 
good work, but a few people or 
groups of people deserve special men- 
tion. Foremost in this group is 
Charles H Moore and, through him, 
the company FORTH Inc. Moore 
developed the language over a long 
period of time (see his article "The 
Evolution of FORTH, an Unusual 
Language," on page 76) and pro- 
moted it through his company 
FORTH Inc. Elizabeth Rather, who 
contributed significantly to the 



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development of the language and 
who is vice-president at FORTH Inc, 
should also be mentioned in this con- 
text. 

Then there is the FORTH Interest 
Group (POB 1105, San Carlos CA 
94070), without whose efforts low- 
cost versions of FORTH would not be 
available. Although many people in 
the group have contributed to its 
working, names that must be men- 
tioned are Bill Ragsdale 
(coordinator), Dave Boulton, Kim 
Harris, John James, and George 
Maverick. Over the past two years, 
this group has collectively raised its 
membership from a few dozen people 
in northern California to over a thou- 
sand members worldwide. In the pro- 
cess, they have also publicized 
FORTH at numerous conventions 
and have distributed public-domain 
versions of FORTH (called fig- 
FORTH) for all the major micro- 
processors; ie: 8080, 6800, 6502, 
9900, PACE, and LSI-11. Although 
they supply only listings and 
documentation, versions customized 
for various popular microcomputers 
are available inexpensively. In addi- 
tion, they are working on standard- 
izing certain extensions to FORTH 
(floating-point numbers, arrays, etc), 
and they publish a very professional- 
looking bimonthly magazine called 
FORTH Dimensions. The group has 
monthly meetings at the Liberty 
House Department Store in 
Hayward, California, on (what else?) 
the fourth Saturday of each month. 
Membership in the FORTH Interest 
Group (which includes a subscription 
to its magazine) is $12 per year, $15 
overseas. 

A final group that must be men- 
tioned is Miller Microcomputer Ser- 
vices of Natick, Massachusetts, 
which sells and supports a version of 
FORTH, called MMSFORTH, and 
other related FORTH products for the 
Radio Shack TRS-80 Model I. Not 
only do they provide a fine version of 
FORTH with arrays, strings, 
graphics, and other extensions, they 
are the only microcomputer-FORTH 
vendor that supports its product with 
both information and new vocabu- 
laries of FORTH words. (For exam- 
ple, they have a set of FORTH words 
that add 6- and 15-digit floating-point 
arithmetic, complex numbers, and a 
full Z80 assembler, all for $29.95.) 
They also publish an MMSFORTH 
Newsletter that always has some 



132 August 1980 © BYTE Publications Inc 



Circle 90 on inquiry card. 




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The single quantity price is only 
$640. Ten-digit display option, $190. For 
more information or literature on the SLC-1 
Time Machine, contact 
Digital Pathways, Inc., 
1260L'Avenida, 
Mountain View, Cali- 
fornia 94043, or phone 
(415)969-7600. 



U 3JCU 
i.i-L.D I 



GET INTO THE TIME MACHINE. 

DIGITAL PATHWAYS 



Circle 91 on inquiry card. 



BYTE Augusl 1980 133 



goodies you'd expect to pay money 
for. The people at MMSFORTH are 
A Richard (Dick) Miller and Judy 
Miller, along with free-lance pro- 
grammer Tom Dowling, who wrote 
MMSFORTH for the TRS-80. 

In addition, the major vendors of 
FORTH should be commended for 
the way they have worked and are 
working together to help standardize 
the language. The people mentioned 
above, along with the European 
FORTH Users' Group (EFUG), have 
met as the International FORTH 
Standards Team to work out a stan- 
dard set of FORTH words (with stan- 
dard behavior) that can be used to in- 
crease the already high portability of 
FORTH programs. Once the pro- 
posed FORTH-79 standard is ap- 
proved by this standards team, 
FORTH Inc, the FORTH Interest 
Group, and Miller Microcomputer 
Services have indicated that they will 
bring out new FORTH versions con- 
forming to this standard. 

Variants of FORTH 

A few other FORTH-like languages 
should be mentioned here. URTH 
(University of Rochester THreaded 



language) is simply FORTH by 
another name. I am told that CON- 
VERS, an experimental language that 
was offered by the Digital Group, is a 
FORTH-like language. 

STOIC is a language that is dif- 
ferent from FORTH primarily in 
some small syntax rules, although its 
enthusiasts claim it is more powerful 
than FORTH. From reading the docu- 
mentation, I have found that STOIC 
interacts differently and has more 
sophisticated disk access than 
FORTH. CP/M Users Group (1651 
Third Ave, New York NY 10028) 
distributes STOIC on two 8-inch 
single-density CP/M floppy disks; 
the cost is $20, which includes 
postage, documentation (on CP/M 
DOC files), and group membership 
fees. STOIC was developed by Roger 
G Mark and Stephen K Burns in the 
Biomedical Engineering Center for 
Clinical Instrumentation, funded by 
the Harvard-MIT Program in Health 
Sciences and Technology in Cam- 
bridge, Massachusetts. 

Also, I am very excited about a 
book nearing publication: Threaded 
Interpretive Languages by Ron 
Loeliger. This book, to be published 



NOBODY CAN MATCH OUR 
DOLLAR/QUALITY RATIO! 

MS-204 PRINTER 

INTRODUCTORY PRICE: 




CABLE: $34.50 

Compatible with TRS-80, Apple, Pet 
or any other Centronics-type system 

Features 

• 132/80 Columns, 63 LPM, Bi-Directional, Nominal Thruput 

• 100% Heavy Duty Cycle- High Reliability, 100 Million Character 
Print Head Life 

• Sprocket Feed; Variable Forms Width, 2.5" - 9.5" 

• Double Width Characters: 40,66 Characters per line 

• 9 x 7 Dot Matrix Character Font 

• 6-Channel Electronic Vertical Format Unit 

• Documentation Included 

Ask about our 8-inch Drives & Software 



M 



ATCHLESS 

YSTEMS 



18444 S. Broadway 
Gardena, CA 90248 
(213) 327-1010 

6 1980 Matchless Systems & MarketPlan 



soon by BYTE Books, delves deeper 
into the practical aspects of designing 
and implementing a threaded lan- 
guage than any book I have seen. Not 
only does it demonstrate exactly how 
the machine code must work, it also 
details the specific implementation of 
ZIP (which looks like FORTH under 
another name) in Z80 assembly 
language. The book promises to be 
the definitive work on how threaded 
languages perform. 

Final Notes 

As we received more and more 
FORTH articles, I realized that we 
would soon have too many for this 
special August issue. I immediately 
scheduled for subsequent nontheme 
issues those extra articles we could 
not use at this time, a process known 
as "holding down the FORTH." In 
any case, we have several FORTH ar- 
ticles that will appear in upcoming 
issues of BYTE. These include an arti- 
cle on recursion in FORTH by George 
Flammer, a tutorial on string- 
manipulating FORTH words by John 
Cassady, a history of the FORTH 
Standards Team by Bill Ragsdale, 
and a detailed discussion of the dif- 
ferent kinds of threaded codes by 
Terry Ritter and Gregory Walker. 

We hope you will enjoy looking at 
the FORTH tapestry presented in this 
issue.! 



Articles Policy 

BYTE is continually seeking quality 
manuscripts written by individuals 
who are applying personal computer 
systems, designing such systems, or 
who have knowledge which will prove 
useful to our readers. For a more for- 
mal description of procedures and 
requirements, potential authors should 
send a large (9 by 12 inch, 30.5 by 22.8 
cm), self-addressed envelope, with 28 
cents US postage affixed, to BYTE 
Author's Guide, 70 Main St, Peter- 
borough NH 03458. 

Articles which are accepted are pur- 
chased with a rate of up to $50 per 
magazine page, based on technical 
quality and suitability for BYTE's 
readership. Each month, the authors of 
the two leading articles in the reader 
poll (BYTE's Ongoing Monitor Box or 
"BOMB") are presented with bonus 
checks of $100 and $50. Unsolicited 
materials should be accompanied by 
full name and address, as well as return 
postage. 



134 August 1980 © BYTE Publications Inc 



Circle 92 on inquiry card. 



CP/M* compatible software 



SYSTEM MAINTENANCE 



DIAGNOSTICS I: Easily the most comprehensive set ot CP/M compatible 
system check-out programs ever assembled. Finds hardware errors in your 
system, confirms suspicions, or just gives your system a clean bill of health. 
Tests 

• Memory • CPU (8080/8085/Z80) • Terminal 

• Disk • Printer 

To our knowledge the CPU test is the first of its kind anywhere. Diagnostics I can 
help you lind problems before they become serious. A good set of diagnostic 
routines are a must in any program library. 

Minimal requirements: 24K CP/M. Supplied with complete user manual 
$60.00 Manual alone: $15.00. 



ACCOUNTING 



ACCOUNTS PAYABLE/RECEIVABLE: A complete, user oriented package 

which features- 
automatic postings to general ledger (optional) 
accounts payable: • check printing with invoice • invoice aging 
accounts receivable: • progress billing • customer statements 

■ partial invoice payments • invoice aging 

The entire package is menu driven and easy to learn and use. It incorporates error 

checking and excellent user displays. This package can be used stand alone or 

with the General Ledger below. 
Supplied with extensive user manual: $200.00. Manual alone: $20.00. 

GENERAL LEDGER: A complete, user oriented package which features: 

• Accepts postings from external programs (i.e. AP/AR above) 

• Accepts directly entered postings 

• Maintains account balances for current month, quarter, and year and previous 
three quarters 

• Financial reports: trial balance, income statement balance sheet, and more. 
Completely menu driven and easy to learn and use. Excellent displays and error 
checking for trouble free operation. Can be used stand alone or with Accounts 
Payable/Receivable above. 

Supplied with extensive user manual: $200.00. Manual alone: $20.00. 
Both require 48K CP/M, terminal with cursor positioning, home and clear home, 
one 8" disk or Two 5" disks. CBASIC2 required. 

TEXT PROCESSING 

TFS — Text Formatting System: An extremely powerful formatter. More 
than 50 commands. Supports all major features including: 

• left & right margin justification • user defined macros 

• dynamic insertion from disk file • underlining and backspace 

TFS lets you make multiple copies of any text. For example: Personalized form 
letters complete with name & address & other insertions from a disk file. Text is 
not limited to the size of RAM making TFS perfect for reports or any big job. 

Text is entered using CP/M standard editor or most any CP/M compatible 
editor. TFS will link completely with Super-M-List making personalized form 
letters easy. 

Requires: 24K CP/M. 

Supplied with extensive user manual: $85.00 Manual alone: $20.00. 

Source to TFS in 8080 assembler can be assembled using standard CP/M 
assembler) plus user manual: $250.00. 

MAILING LIST 

SUPER-M-LIST: A complete, easy to use mailing list program package. 
Allows for two names, two address, city, state, zip and a three digit code field for 
added flexibility Super-M-List can sort on any field and produce mailing labels 
direct to printer or disk file for later printing or use by other programs Super-M 
List is the perfect companion to TFS. Handles 1981 Zip Codes! 

Requires: 48K CP/M. 

Supplied with complete user manual: $75.00. Manual alone: $10.00 

UTILITIES 

Utility pack #1 : A collection of programs that you will find useful and maybe 
even necessary in your daily work (we did 1 ). Includes 



PROGRAMMING LANGUAGES 



• recursive procedures/functions • 

• FOR (loop) 
•IF... THEN... ELSE 

• READ & WRITE 



CMP- Compare two files for equality. 
ARCHIVER Compacts many files into one. useful when you run out of directory 
entries 
SORT In core sort of variable length records 
XDIR Extended, alphabetical directory listing with groupings by common 
extension. 
PRINT Formatted listings to printer. 
PG Lists tiles to CRT a page at a time 
. . plus more 
Requires- 24K CP/M _- T 

Supplied with instructions on discette $50 00 TlrSt IM OOltWare leClinOIOCjy 

Circle 93 on inquiry card. 



SuperSoft 



FORTH: a full, extended FORTH interpreter/compiler produces COMPACT, 
ROMABLE code. As fast as compiled FORTRAN, as easy to use as interactive 
BASIC. 

SELF COMPILING: Includes every line of source code necessary to recompile 

itself. 

EXTENSIBLE: Adds functions at will. 

Z80 & 8080 ASSEMBLERS included 

Single license, OEM licensing available 

Please specify CPU type: Z80 or 8080 

Supplied with extensive user manual and tutorial: $150.00 

Documentation alone: $25.00 

ENHANCED 'TINY' PASCAL: We still call it Tiny' but it's bigger and better 
than ever! This is the Famous Chung/ Yuen Tiny' Pascal with more features 
added. Features include: 

•integer arithmetic -CASE 
•sequential disk I/O • one dimensional arrays 
•WHILE • 'PEAK' & POKE' 

•REPEAT... UNTIL -more 
'Tiny' Pascal is fast. Programs execute up to ten times faster than similar BASIC 
programs. 

SOURCE TOO 1 We still distribute source, in Tiny' Pascal, on each discette 
sold. You can even recompile the compiler, add features or just gain insight into 
compiler construction. 

Tiny' Pascal is perfect for writing text processors real time control systems, 
virtually any application which requires high speed. Requires: 36K CP/M. Supplied 
with complete user manual and source on discette: $85.00. 
Manual alone: $10.00. 

SOFTWARE SECURITY 

ENCODE/DECODE: A complete software security system for CP/M. Encode/ 
Decode is a sophisticated coding program package which transforms data stored 
on disk into coded text which is completely unrecognizable. Encode/Decode 
supports multiple security levels and passwords. A user defined combination 
(One billion possible) is used to code and decode a file. Uses are unlimited. Below 
are a few examples: 

• data bases • general ledger • inventory 

• payroll files • correspondence • accounts pay/rec 

• programs • tax records • mailing lists 
Encode/Decode is available in two versions: 

Encode/Decode I provides a level of security suitable for normal use. 
Encode/Decode II provides enhanced security for the most demanding needs 
Both versions come supplied on discette and with a complete user manual. 

Encode/Decode I: $50.00 

Encode/Decode II: $100.00 Manual alone: $15.00 

— INTERCOMPUTER COMMUNICATIONS 

TERM: a complete intercommunications package for linking your computer to 
other computers. Link either to other CP/M computers or to large timesharing 
systems. TERM is comparable to other systems but costs less, delivers more and 
source is provided on discette! 

With TERM you can send and receive ASCII and Hex files (COM too. with 
included convertion program) with any other CP/M computer which has TERM ot 
compatible package. Allows real time communication between users on separate 
systems as well as acting as timesharing terminal. 

• Engage/disengage printer • error checking and auto retry 

• terminal mode for timesharing between systems • conversational mode 

• send files ■ receive files 
Requires 32K CP/M. 

Supplied with user manual and 8080 source code $11 00 

Manu al alone: $15.00. 

CP/M Formats: 8" soft sectored, 5" Northstar, 
5" Micropolis Mod II, Vector MZ 
All Orders and General Information: 
SUPERSOFT ASSOCIATES 
P.O. BOX 1628 
CHAMPAIGN, IL61820 
(217)359-2112 

Technical Hot Line: (217) 359-2691 
(answered only when technician is available) 

"CP/M REGISTERED TRADEMARK DIGITAL RESEARCH 




VISA 



BYTE August 1980 135 



[ALwOi) 

COMPUTER SYSTEMS 



*Z80 is a registered trademark of Zilog, Inc. 

"CP/M and MP/M are registered trademarks ot Digital Research. Inc 




ALTOS BREAKS 
THE MICRO 
BARRIER. 



3 



Yesterday, microcomputer meant micro 
performance. Once you outgrew it, you had to step 
up to a mini. Which meant a big step up in price. 

Today, there's the new Altos ACS8000-6 single- 
board microcomputer system. 

It's the first system for the OEM, small business- 
man and personal user, that offers minicomputer 
performance and minicomputer storage capacities— 
at a microcomputer price. 

MULTI-USER, WINCHESTER STORAGE, 
FLOPPY BACK UP: $14,260. 

The new Altos ACS8000-6 is a highly advanced 
Z80* based microcomputer system with high-speed 
RAM, floppy disk and Winchester hard 
disk controllers, DMA, six serial and 
two parallel I/O ports and the AMD 
9511 floating point processor all on 
a single board. A typical four-user 
system configuration with two 
megabytes of Shugart floppy 
and 29.0 megabytes of Shugart 
Winchester storage, including 
CPU and 208K bytes of RAM, 
costs only $14,260— com- 
pared to $30,000 or more for 
a similar minicomputer system. 
And that adds up to mini 
performance at less than half 
the cost! 

MULTI-USER EXECUTIVE 

SUPPORTS FOUR 
INDEPENDENT USERS 
RUNNING CP/M** 
COMPATIBLE PROGRAMS. 

This revolutionary new microcomputer system 
features the MP/M** Multi-User Executive software 
program that's unique in two ways. It includes a 
multi-user CP/M capability and the ability to handle 
Winchester-type hard disks. The advanced Z80 
operating program supports four independent CP/M 




compatible programs in any of six popular lan- 
guages: BASIC, FORTRAN, COBOL, PASCAL, APL, 
C, and a large assortment of additional business 
application packages. MP/M is compatible with both 
the 1.4 and 2.0 versions of Digital Research's 
CP/M, which means programs based on either 
version can run under MP/M without modification. 

With MP/M at the helm, your Altos 
ACS8000-6 system can support up to four simul- 
taneous users with 48K bytes of RAM each plus 
58 megabytes of Winchester storage and 4 mega- 
bytes of floppy back up. And that adds up to the 
first microcomputer to give you the power and 

performance of a minicomputer. 
SINGLE-USER, HARD-DISK 
SYSTEMS START AT $9450. 
The Altos ACS8000-6 
series. It's a barrier breaker 
i n every sense. Our entry- 
level, single-user, hard-disc 
system with floppy back 
up is priced under $10,000 
and even our 4-user CP/M 
model is available for 
under $12,000. And all 
configurations are easily 
upgraded. For specific 
details about pricing or 
performance, call or write: 
Altos Computer Systems, 
2360 Bering Drive, San Jose, CA 
(408) 946-6700. TELEX 171562 ALTOS SNJ. 



(altoS) 

COMPUTER SYSTEMS 



Circle 94 on inquiry card. 





BASF Systems 
Bedford MA 


Corvus Systems, Inc. 
San Jose CA 


IBM Corporation 
General Systems Div 


International 

Memories Inc (IMI) 

Cupertino CA 


Model 


6171/6172 


11T 


4963 29A/64A 


7710/7720 


Unformatted Capacity 
(millions of bytes) 


8/24 


11 


29/64 


11/20 


Platter Size 


210mm (8.27 inch) 


200mm (7.87 inch) 


210mm (8.27 inch) 


200mm (7.87 inch) 


Number of Platters 


1 or 2 


2 


3 or 6 


2 


Average Access Time 


42 ms 


50 ms 


27 ms 


50 ms 


Maximum Data Transfer Rate 
(K bytes per second) 


800 


648 


1030 


648 


Average Latency 


8.3 ms 


8.3 ms 


9.7 ms 


8.3 ms 


Rotational Speed 


3600 rpm 


3600 rpm 


approx. 3100 rpm 


3600 rpm 


Motor Type 


brushless DC 


brushless DC 


— 


brushless DC 


Spindle Drive 


direct drive 


direct drive 


— 


direct drive 


Actuator Type 


linear voice coil 


linear voice coil 


rotary voice coil 


linear voice coil 


Positioning Mechanism 


servo 


servo 


servo 


servo 


Density bpi 


6542 


5868 


8530 


5868/6000 


Density tpi 


500 


300 


450 


300 


Physical Size 
(inches) 


4.59 by 8.99 by 18 


5.5 by 8.57 by 1 9.25 


— 


5.5 by 8.57 by 19.25 


Weight (pounds) 


20 


22 


— 


22 


Single Quantity Price 


— /$3,100' 


$5,350' 


approx. $9,300/$10,700 


$2,990/$3,590 


OEM Discount Price 


Competitive OEM 
discounts available 


— 


— 


$1,900/82,290(100) 


Cost Per Thousand Bytes 
(OEM Discount) 


— 1— 


— 


— 


8.173/8.112 


Comments 


Available with integrated 
SMD interface @$3,500 
and integrated controller 
with host bus interface for 
$3,900; all prices quoted 
are for 24 megabyte 

Model 6172. 

1. Includes disk bus 

interface 


Up to 4 drives per 

subsystem. Add-on drives 

@$2,990. Uses IMI 7710 

drive. 

2. Complete subsystem 


ntegrated into System/34. 

Add-on peripheral for 

Series 1. 


Optional integrated 

controller available 

@S500 (quantity 1); 8325 

(quantity 100). Power 

supply @$250 



Text continued from page 70: 

• hardware-oriented control 
status 



and 



The main characteristics for the host 
level are: 

• parallel data transfer 

• formatting/de-formatting 
included in drive electronics 

• function-oriented control and 
status by functional command 
like read/write sector and 
format 

Device-level interfaces can be 
divided into four groups: 

• ANSI 

• ANSI-like 



• SMD 

• Floppy-disk-like 

The ANSI interface, as far as it is 
currently defined, will use a single 
50-conductor flat cable. Up to four 
drives can be connected in a daisy- 
chain configuration. Differential 
drivers and receivers will be used 
only for block and data signals for 
read and write functions. All other 
lines will use standard TTL 
(transistor-transistor logic) signals. 
Control commands and status infor- 
mation will be transferred over an 
8-bit-wide bidirectional bus. The bus 
control lines use an asynchronous 
handshake mechanism, allowing sim- 
ple adaptation of the bus speed to any 
microprocessor. Data is transferred in 



serial NRZ (nonreturn-to-zero) for- 
mat separated from the clock signal. 

In the ANSI-like interface, most of 
the current device-level interfaces are 
more or less similar to the ANSI inter- 
face. Common to all are an 8-bit 
parallel control bus and serial NRZ 
data transfer. 

SMD (storage module drive) inter- 
face is a de facto industry standard 
for 14-inch drives and is being 
adapted for 14-inch drives by ANSI. 
It has also been implemented for 
8-inch drives. The SMD interface uses 
differential drivers and receivers for 
all signals. (They give excellent per- 
formance as regards high speed, long 
cable lengths, and high noise immuni- 
ty.) The drives are connected through 



138 August 1980 © BYTE Publications lnc 



Kennedy Co 
Altadena CA 


Microcomputer Syst 
Corp 
Sunnyvale CA 


3ms 


Micropolis Corp 
Chatsworth CA 


Pertec Computer Corp 
Chatsworth CA 


Priam 
San Jose CA 


7000 


MSC-8000 




1 201 -1/1 202-1/1 203-I 


D8000 


2050/3450 


4/12/20 


40 




9/27/45 


20 


20/34 


210mm (8.27 inch) 


8 inch 




200mm (7.87 inch) 


210mm (8.27 inch) 


8 inch 


1, 2, or 3 


3 




1, 2, or 3 


2 


2 or 3 


50 ms 


25 ms 




42 ms 


50 ms 


50 ms 


— 


1200 




922 


870 


1030 


8.3 ms 


— 




8.3 ms 


— 


6.4 ms 


3600 rpm 


— . 




3600 rpm 


— 


4700 rpm 


AC 


— 




brushless DC 


— 


brushless DC 


belt drive 


— 




direct drive 


— 


direct drive 


rotary 


— 




rotary voice coil 


— 


linear voice coil 


servo 


— 




servo 


servo 


servo 


5280 


— 




8626 


6000 


6370 


300 


— 




478 


476 


480 


5.25 by 8.5 by 16.5 


— 




4.62 by 8.55 by 14.25 


4.62 by 8. 55 by 14.25 


4.62 by 8.55 by 14.25 


20 


— 




22 


— 


20 


$2,100/$2,300/$2,650 


— 




$1,962/$2,591/$3,007 


$3,000 


$3,000/$3,750 


$1,680/$1,840/$2,120(100) 


— 




— 


$1,800 


$2,200/$2,750(100) 


$.42/$.153/$.106 


— 




— 


$.09 


$.11/$.08 




Included in package is 
an 80 megabyte, V2 inch 
magnetic-tape drive on 
the same motor spindle 
for removable back-up 
storage 


Available with integrated 

controller as Models: 

1221-1 $2,834; 1222-1 

$3,463; 1223-1 $3,879, 

single quantities 






Table 4: Specifications ana 


characteristics of high-end, 


8-inch hard-disk drives. 





one daisy-chain cable for control and 
one radial cable for read/write and 
additional control. Control informa- 
tion is transferred on a 10-bit-wide 
unidirectional synchronous bus. Data 
is transferred in serial NRZ format. 

The SMD interface allows very 
high transfer rates and long cable 
lengths. Because SMD uses differen- 
tial drivers and receivers for all 
signals, it is somewhat more costly 
than other interfaces using TTL cir- 
cuits. Because of the 10-bit syn- 
chronous bus structure, SMD is not 
easy to interface to current 8-bit pro- 
cessors. The main advantage of SMD 
for 8-inch drives is that it is a stan- 
dard, and controllers are readily 
available for easy integration into ex- 
isting or currently supplied systems. 



Having a floppy-disk-like interface 
for 8-inch hard disks allows the com- 
bination of floppy-disk drives and 
hard-disk drives in one system. 
Because of the differences in transfer 
rates and other parameters, floppy- 
and hard-disk drives are not fully 
interface-compatible. Hard-disk users 
must add a radial cable for differen- 
tial read/write signals in addition to 
the normally used daisy-chain cable. 
By adding 15% to 20% more cir- 
cuitry, a hard-disk controller can be 
designed to also control floppy-disk 
drives. However, a floppy-disk con- 
troller cannot handle a Winchester- 
type hard-disk drive. 

In comparing floppy-disk-like in- 
terfaces with other device-level inter- 
faces, there are three major differ- 



ences. First, with floppy-disk-like in- 
terfaces there is no control bus be- 
cause commands and status signals 
are transferred on discrete lines. 
Second, positioning control is 
achieved with step and direction 
signals as opposed to the transfer of a 
parallel-cylinder address with other 
interfaces. Third, data is transferred 
in the raw format as recorded on the 
disk. This implies that synchroniza- 
tion, separation (or generation) of 
clock and data, and generation and 
detection of sector and address marks 
must all be performed externally to 
the drive. The floppy-disk-like con- 
cept minimizes drive electronics, but 
puts the burden of developing and 
producing the balance of the required 
electronics on the user. 



August 1980 © BYTE Publications Inc 139 



Anatomy 
of a 

Threaded 
Language 



********** 






Threaded languages (such as 
FORTH) are an exciting new class of languages. 
They are compact and fast, giving the speed of assembly 
language with the programming ease of BASIC, and combine features 
found in no other programming languages. An increasing number of people are using 
them, but few know much about how they work. Is a threaded language interpreted or compiled? 
How much memory overhead does it require? Just what is an "inner interpreter"? Threaded In- 
terpretive Languages, by R. G. Loeliger, concentrates on the development of an interactive, ex- 
tensible language with specific routines for the ZILOG Z80 microprocessor. With the core inter- 
preter, assembler, and data type defining words covered in the text, it is possible to design and im- 
plement programs for almost any application imaginable. Since the language itself is highly 
segmented into very short routines, it is easy to design equivalent routines for different processors 
and produce an equivalent threaded interpretive language for other development systems. If you 
are interested in learning how to write better FORTH programs or you want to design your own 
powerful, but low-cost, threaded language specific to your needs, this book is for you. 




This and other BYTE/McGraw-Hill 
books are available from BYTE 
Books or your local computer store. 

Please send □ 



ISBN 0-07-038360-X 
Price $18.95 

copies of Threaded Interpretive Languages 



Name 



Title 



Company 



Street 



Available in Nov. 1980 



City 



mniMi 



70 Main St, 

Peterborough, NH 03458 _. 



State/Province 



Code 



i ! Check enclosed in the amount of S 
□ Bill Visa I J Bill Master Charge 

Card No 

Exp. Date. 



Add 75<t per book to cover postage and handling. 
Please remit in U.S. funds or draw on a U.S. Bank. 



B8 



A NEW WORLD OF 5AAALL COMPUTERS 
IS AT YOUR FINGERTIPS THIS FALL 




V 4th Annual 

NATIONAL SMALL COMPUTER SHOW 



New York Coliseum, October 30 to Nov. 1 , 1 980 



When we say "fingertips" we mean just that: a hands-on-inspection 
opportunity for you to try the small computers and systems that will 
write the history of microprocessing in the 1 980's. 

Manufacturers will fill over 30,000 square feet with computers, soft- 
ware and peripherals. Amazing strides in technology are reflected in 
exhibits and lecture series. 

New hardware and software for business, education, the sciences 
and professions, graphics and personal use are being gathered for 
the largest and most beautifully presented National Small Computer 



Show ever produced. 

As always, the show contains attractions for the seasoned compu- 
ter professional, as well as those who wish an introduction to the 
exciting world of small computers for business, professional or 
personal use. In just a short time, you can discuss your interest with 
many industry leaders, vendors, technologists, and our expert 
lecturers. 

Registration fee is only $10 per day, and all registrants have free 
access to the hourly lectures. 



FREE LECTURES FOR VISITORS 



Introduction to Small Systems for Business, Stan Velt, Associated Computer Ind., noon, Oct. 30 & 31 . 

Mailing Lists: Several Directions. Dr. Norman Agin. Mathtech. Inc., noon, Oct. 30&2pm, Oct. 31. 

Selecting A Small Computer for Business, David Benevy, Computer Mart of NJ, 1 pm, Oct. 30 & 31 . 

Evaluating and Improving Your Computer's Performance, Philip Grossman, Raytheon Co., 1 pm, Oct. 30. 

Law Office Systems Aspects of Word Processing, Bernard Sternln, 2 pm, Oct. 30. 

Future Smart Machines: 2000 A.D. and Beyond, Dr. Earl Joseph, Sperry Univac, 2pm, Oct. 30. 

Computer Contracts - Facing the Issues, Alan C. Verblt, Verbit & Co., 3 pm, Oct. 30. 

Acc'ts Receivable/ Acc'ts Payable/Gen'l Ledger. 3pm, Oct. 30. 

Advantages of Distributed Processing & Multi-Processing, John Steefel, Ql Corp., 4 pm, Oct. 31 . 

Investment Analysis of Stocks & Commodities on a Microcomputer, Fred Cohen, Shearson Loeb Rhodes, 

Inc., 4 pm. Oct. 30, 3 pm, Oct. 31. 
BASIC Programming, Michael Mulcahey. Worcester State College, noon, Oct. 31 . 
Vldeoprlnts: Full-Color, Low-Cost, Hard-Copy Computer Graphics, Warren Sullivan, Image Resource 
Corp. ,1pm, Oct. 31. 
Business Applications Software Development Via Data Base Management, Dr. Andrew Whlnston, Micro 

Data Base Systems, 2 pm, Oct. 31. 



Application of PASCAL to Small Systems for Business, Panel, Stan Veit, Associated Computer Ind., 

Moderator, 3 pm, Oct. 31. 
Educational Software: the Good, the Bad, the Ugly, Jo Ann Comito, S.U.N.Y. at Stony Brook, noon, 

Nov. 1. 
Introduction to Personal Computing, noon, Nov. 1. 
Computer-Assisted Mathematics Courses, Dr. Frank Scalzo, Queensborough Community College, 

1 pm, Nov. 1. 
Artificial Intelligence Update, Prof. Peter Kugel, Boston College. 1 pm, Nov. 1 . 
Compiling and Retrieving Personal Medical Data with a Microcomputer, Derek Enlander, MD, St. Luke's 

Hospital, 2 pm. Nov. 1. 
The Present State of CP/M Compatible Software, Tony Gold, Lifeboat Associates, 2 pm, Nov. 1. 
High Volume Data Handling: Intro, to File Processing, Prof. Peter Kugel, Boston College, 3 pm, Nov. 1. 
Connecting the Computer to the Outside World, Prof. James Gips. Boston College. 3 pm, Nov. 1. 
Educational Applications In the Home, David Ahl, Creative Computing Magazine, 4 pm, Nov. 1 . 
Household Applications - Some of Them New, Dr. Dennis J. McGuIre, 4 pm, Nov. 1. 
(Additional lectures to be announced) 



SPECIAL: EXECUTIVE EDUCATION SESSION FOR BUSY PEOPLE 

NSCS offers an Intensive five-hour Introduction to computers tor the executive whose time Is limited, but wants to learn how to cope on various levels in business with computers. Covers basics 
In computer hardware and software, determining your needs, how to buy, how to upgrade, how to get the most out of systems. Given lour times, Oct. 29 to Nov. 1 . Fee $200, including run-of- 
show registration. Call or write lor Information. Attendance limited. 



r REGISTRATION FOR AMERICA'S BIGGEST SMALL COMPUTER SHOW 1 

Please register me for the 4th Annual National Small Computer Show, Oct. 30 ■ Nov. 1 , 1980 New York Coliseum. 



NAME 



COMPANY (If Any)_ 
ADDRESS 



(Check main Job function) 

1 D Accountant/CPA 

2 G Advertising 

3 □ Administrator (Business) 

4 D Architect/Builder 

5 D Art Director 
5 □ Banker 

7 D Chemist 

8 □ Commodities Broker 

9 Q Communications 

10 D Computer Dealer 

1 1 D Computer Distributor 

1 2 D Computer Hardware Consult. 

13 DComputerOEM 

1 4 D Computer Software Consult. 



1 5 □ Computer Systems Consult. 

1 6 D Computer Technician 

17 D Data Processing Mgr. 

18 D Electronic Engineer 

19 □ Engineer 

20 □ Financial Manager 

21 D Industrial Des, 

22 D Lawyer/Law Office Mgr. 

23 □ Manufacturer 

24 □ Marketing 

25 D Medical Doctor 

26 D Medical Technician 

27 □ Military 

28 □ Office Manager 



BUSINESS TITLE (If Any)_ 
TELEPHONE 



_ZIP_ 



29 D Public Servant 

30 □ Real Estate 

31 D Religious 

32 □ Research/Development 

33 D Scientist 

34 D Stock Broker 

35 □ Teacher 

36 D Transportation 

37 D Utility 

38 D WP Manager 

39 □ WP Operator 

40 □ Student 

41 D Other (Please specify) 




DONE DAY $10 D TWO DAYS $20 1 

D THREE DAYS $30 
Mail with payment of $10 for each day you I 
wish to attend. Use one form per person. I 
Registration badge will be sent by mail in I 
early October. Check or money order) 
only. Mall prior to October 1 0, 1 980. 

Foreign orders: October 1, 1980. 1 
National Small Computer Show 
110 Charlotte Place 
Englewood Cliffs, NJ 07632 j 

201-569-8542 j 



Circle 95 on inquiry card. 



BYTE August 1980 141 





Century Data Systems 
Anaheim CA 


Century Data Systems 
Anaheim CA 


Fujitsu America Inc 
Santa Clara CA 


Model 


Marksman M-10/M-20/M-30 


Hunter H-32/H-64/H-96 


M2282/M2283/M2284 


Unformatted Capacity 

(millions of bytes) 


10/20/30 


34/67/100 


66/133/166 


Platter Size (inches) 


14 


14 


14 


Number of Platters 


1, 2, or 4 


2, 3, or 4 


— 


Average Access Time 


60 ms' 


30 ms 


27 ms 


Maximum Data Transfer Rate 


960 


1209 


1012 


(K bytes per second) 








Average Latency 


12.5 ms 


8.3 ms 


10.12 ms 


Rotational Speed 


2400 rpm 


3600 rpm 


3000 rpm 


Motor Type 


— 


— 


— 


Spindle Drive 


— 


— 


— 


Acutator Type 


band 


— 


rotary 


Positioning Mechanism 


stepper motor 


servo 


servo 


Density bpi 


— 


— 


6475 


Density tpi 


— 


— 


668 


Physical Size (inches) 


8 by 16.5 by 21.5 


10.5 by 17.5 by 30 


10.3 by 18.9 by 26.6 


Weight (pounds) 


45 


175 


100 


Single Quantity Price 


— 


— 


$4,350/$5,200/$5,500 


OEM Discount Price 


— 


— 


$3,450/$4,300/$4,600 
(quantity 100) 


Cost Per Thousand Bytes 
(OEM Discount) 


— 


— 


$.052/$.033/$.028 


Comments 


Winchester Technology 
includes settling time 


16.7 megabytes of removable 

storage on each model 

(5440 Type) 


Optional 655 K byte fixed head 
storage for $700 



Host-Level Interface 

A typical implementation for host- 
level interface is the BASF 6170 series 
drive with integral formatter/con- 
troller. The BASF host bus interface 
uses a single daisy-chain cable that 
can connect one or more units to the 
host adapter. Transfer of data, com- 
mand, and status information is done 
across one common 8-bit-wide bi- 
directional asynchronous bus. The 
eight bus lines, as well as additional 
lines for bus control and interrupt 
generation, all use standard TTL 
drivers and receivers. Using a host- 
level interface is the easiest and fastest 
way to interface an 8-inch Winchester 
drive to a given host system. 

How Intelligent Should a Con- 
troller Be? 

With the decreasing cost of 
microprocessors and memories, the 
trend is toward the use of intelligent 
subsystems to handle all I/O-related 



functions, rather than tying up the 
processor. 

These subsystems can communi- 
cate with the main system through a 
high-level command language (eg: 
one that is file-oriented as opposed to 
hardware-oriented). Functions such 
as automatic backup, automatic error 
recovery, power-on bootstrap load- 
ing, etc, can be completely controlled 
locally in the subsystem, thus taking 
the burden off the main processor and 
improving the system's performance. 

Further improvement can be gained 
by adding hardware and software for 
such things as double-buffering for 
data transfer, overlapped operation 
in a multiple drive configuration, and 
RPS (rotational-positioning sensing) 
for access optimization. 

There is a limit to the transparency 
of the disk system to the operating 
system. If a disk with higher packing 
density is substituted, the number of 
sectors on each track or the number 



of tracks per surface will likely be dif- 
ferent. This information must be 
communicated to the operating 
system. (With luck, this is a small 
parameter change in the I/O driver of 
a well-designed, modular operating 
system). But, however easy or dif- 
ficult it is to change, it must be done 
to take full advantage of the new 
higher-capacity drive. 

The Question of Backup for Fixed 
Disks 

The usefulness of removable media 
on fixed-disk-based systems arises 
from three needs: 

• system backup for crash/ fault 
recovery 

• program and data-base 
dissemination 

• archival storage of information 

The excellent reliability record of 
Winchester-technology disks is caus- 



142 August 1980 © BYTE Publications Inc 



Fujitsu America Inc 
Santa Clara CA 




Kennedy Co 
Altadena CA 


Priam 
San Jose CA 


Shugart Associates 
Sunnyvale CA 


M2201/M2211 




5300 


3350/6650/15450 


SA4000 


50/83 




14/42/70 


33/66/1 54 


14.5/29 


14 




14 


14 


14 


2 or 3 




1, 2, or 3 


1 


1 


30 ms 




70 ms 


50 ms 


87 ms 


819 




— 


1030 


— 


12.5 ms 




10 ms 


9.7 ms 


— 


2400 rpm 




3000 rpm 


approx. 3100 rpm 


— 


— 




AC 


brushless DC 


— 


— 




— 


direct drive 


— 


linear motor 




rotary 


linear voice coil 


band 


servo 




servo 


servo 


stepper motor 


6135 




6000 


6370 


5534 


370 




300 


480/960/— 


172 


10.3 by 19 by 30.2 




7 by 19 by 22 


6.8 by 16.6 by 20 


— 


150 




75 


33 


— 


$5,400/$7,200 




$3,200/$3,700/$4,200 


— 


— 


$3,900/54,990 (quantity 1 


30) 


$2,560/$2,960/$3,360 
(quantity 100) 


$1,800/—/— 


— 


$.078/$.060 




$.183/$.07/$.048 


$.055/—/— 


— 


Front-loading cartridge 
removable storage 




Winchester Technology 


Winchester Technology 


Winchester Technology 




Table 5: 


Specifications and characteristics 


of 14-inch, hard-disk drives. 





ing some system builders and users to 
take a fresh look at backup re- 
quirements for data storage. They are 
concluding that, for some applica- 
tions, it is no longer necessary to in- 
clude removable media for backup 
protection in systems design. 

Error-correcting capabilities of sys- 
tem software and intelligent control- 
lers help to eliminate the need for 
backup in some cases. However, 
there will probably always be appli- 
cations — perhaps the majority — in 
which backup cannot be eliminated. 
Many systems require removable me- 
dia for program and data-base dis- 
semination and/or archival storage in 
addition to any backup considera- 
tions. Therefore, it seems that there 
will be a continuing need for remov- 
able-media storage peripherals on 
some fixed-disk-based systems. 

According to many small-system 
designers and users, system backup is 
needed regardless of the hardware 



reliability of the fixed-storage subsys- 
tem. System crashes or failures can be 
caused by software bugs and human 
error as well as by hardware faults. 

Until the new wave of small 
Winchester disks came on the scene 
beginning about a year and a half 
ago, the small-systems hard-disk 
market was being served primarily by 
products based on IBM 5440-type 
removable-cartridge disk technology. 
Most of these products have the uni- 
que characteristic of having 50% of 
their spindle capacity removable — in 
other words, they have built-in 
backup. But the major drawbacks to 
their use in small systems are relative- 
ly low performance (70 ms average 
access time); relatively high cost per 
byte; large physical size; and high 
maintenance costs that get higher as 
field engineering labor costs grow. 
Even with the introduction of cost-ef- 
fective, small, reliable Winchester- 
type products, these 5440-based pro- 



ducts still have a place in some small 
systems. After all, the backup pro- 
blem is solved, whereas no generally 
accepted backup method has yet 
emerged for the "mini Winnies" to 
make most customers feel comfort- 
able. It is a problem yet to be solved. 

Several approaches are being tried 
for backup. There are floppy disks, 
tape cassettes, tape cartridges, reel- 
to-reel tape drives, and, in at least 
one case, videocassettes. 

The ideal characteristics of a 
backup device are: 

• The cost of the modular 
removable medium should be 
low (less than $20). 

• The cost of the transport device 
should be low. 

• The data-transfer rate should be 
similar to the transfer rate of the 
disk. 

• A single removable module 
should hold more, or at least as 



Augusl 1980 © BYTE Publications Inc 143 



Error Rates 








Recoverable Unrecoverable 


Seek Errors 






1 in 10'° bits 1 in 10' 2 bits to 1 in 

10" bits 


1 in 10 6 seeks to 1 in 
10 7 seeks 






Maintainability 








Preventive Maintenance (MTBF) (Mean Time 

Between Failures) 
(sealed modules) 


(MTBF) (Mean Time 

Between Failures) 

(product) 


(MTTR) (Mean 
Time to 
Repair) 


Component Life 


None 25,000 hours 


8000 to 10,000* 
POH (power-on hours) 


'/a to 1 hr 


5 years 


* Exception: Kennedy 7000 Series, 1500 hours 








Table 6: Reliability data for hard-disk drives. 









Call on John D. Owens for all Your Computer Needs 



COMPUTERS, PRINTERS, CRTs, MODEMS, MAINFRAMES, 

MEMORY, CONTROLLERS, FLOPPY AND HARD DISK 

DRIVES, I/O, DISKETTES AND SOFTWARE. 



IMS 5000 and 8000 Systems 

The new rising starsl Beautifully designed and constructed with the Industrial Micro 
System reputation for fine quality. These systems feature a Z80 CPU, S-100 bus; double 
density drives (either single or double sided) CP/M®. 5000 series uses mini floppies, 
8000 uses maxi floppies. 

Model 5-00125 with two double density drives, 32K Static RAM $2,765 

Model 8-00125 as above but with 8" drives $4,185 

Other configurations available. 



TELETYPE Model 4320 AAK .. $1,185 
Model 4330 punch/reader. 10 or 30 CPS. 

8 level, 1" tape $2,595 

Limited supply of Model 45 available. 

DRIVES 

Per Sci 277 $1,210 

Siemens $395 Shugart $525 

MPI B51 . . . . $265 B52 $365 

Innotronics and QUME also available 

HAZELTINE 1500 $885 

1510 $980 1520 $1,210 

DEC LA 35/36 Upgrade $750 

Increases baud rate to 1200. Microproces- 
sor controlled. Many features include 
TOF, tabs and margin control. 



IBM 3101 CRT Model 10 $1,195 

Model 20 $1,395 

Selectric-like, detached keyboard. 9x16 
dot matrix. Maintenance contract from 
IBM only $70 per year. 



TELEVIDEO SMART CRTs 
912 B and C 


. . $780 


920 B and C 


<R«sn 




IMS MEMORY 16 K static .... 

32 K static 

64 K Dynamic with parity . . . 


$285 

$585 

. . $950 


TEI MAINFRAMES, S-100 

12 slot 


. . $500 


22 slot 


S670 





TARBELL 

Double density controller . 



$420 



COMPLETE SYSTEMS AND WORD PROCESSORS 
CONFIGURED FOR YOUR PARTICULAR APPLICATION 



We have no reader inquiry number. 

Call on us for product sheets. 

Dealer inquiry invited. 

Prices subject to change without notice. 



CODs accepted at no extra charge. 

Shipping $14 for light printers and CRTs . 

Credit cards add 4%. 

NY residents add tax. 



WE EXPORT: 



Overseas Callers: 
Phone 212 448-6298 



TWX 710 588 2844 

or Cable: OWENSASSOC 



We Are Known for Our Prompt and Courteous Service! 



JOHN D. OWENS 

83 Associates, Inc. 21 

12 Schubert Street 
Staten Island, New York 10305 



212 448-6283 



212 448-6298 



much, data as the fixed disk, 
preferably an integer multiple of 
the disk capacity (ie: a 100-mega- 
byte videocassette to back up a 
20-megabyte disk). 

With the relatively unsophisticated 
operating-system software present in 
many small systems today (though 
this is rapidly changing), the backup 
strategy is usually to write the entire 
contents of the disk to a removable 
backup medium on a daily basis. This 
procedure results in a significant loss 
in system availability (while dumping 
or restoring) unless the backup device 
has a fast transfer rate and a large 
capacity. 

Perhaps the most appropriate 
backup for a small Winchester is a 
device that can be included in the 
same package, sharing the same 
spindle drive mechanism and/ or 
some of the same electronics. For the 
low end this may be a floppy disk; for 
the high end it can be a cartridge tape 
drive or a streaming reel-to-reel tape 
drive. But, except for the very low 
end where system cost is a prime con- 
sideration, a small-capacity, slow 
floppy disk is not an ideal backup for 
a large, fast, fixed disk. Streaming 
tape drives may be good backup 
devices for high-performance, high- 
capacity hard disks, but they are too 
expensive for most personal com- 
puter systems. Nevertheless, some 
streaming tape drives are becoming 
available. Kennedy Company of 
Monrovia, California, is delivering 
(60 to 90 days) its Model 6809 Data 
Streamer. It is a microprocessor- 
controlled reel-to-reel (10.5-inch 
reels) tape transport with formatter 
for reading, writing, and controlling 
the 9-track, 100 ips (inches per 



144 August 1980 © BYTE Publications Inc 



second), 1600 character per inch, 
ANSI- and IBM-compatible half- 
inch tape drive. It has an unformatted 
capacity of 46 megabytes per reel. It 
can transfer 12 megabytes in 75 
seconds and 40 megabytes in 250 
seconds. It costs about $2500 in OEM 
quantities. Data Electronics Inc 
(DEI), of Pasadena, California, is 
marketing a 34-megabyte streaming 
microtape cartridge drive for $1219 
(OEM quantities). Cypher Data Pro- 
ducts Inc of San Diego, California, 
produces a 37-megabyte streaming 
reel-to-reel tape drive for under $2000 
(OEM quantities). IBM's answer to 
the backup problem for its 8-inch disk 
drive is the model 8809 streaming 
tape drive. 

The Products and the Companies 

The specifications in tables 3, 4, 
and 5 speak for themselves. There are 
a few special features of some of these 
products worth mentioning. BASF 
Systems of Bedford, Massachusetts 
(whose parent corporation, the BASF 
Group based in Germany, invented 
magnetic recording tape in 1934), 
established a Memory Division in 
early 1979 to manufacture computer- 
disk drives. Their first product is the 
6170 Series 210 mm Fixed-Disk 
Drives available in 8- and 24-mega- 
byte versions. The 24-megabyte ver- 
sion with the integrated, micro- 
programmed BASF host-bus interface 
and controller at $3900 (single quanti- 
ty price, substantial discounts 
available for OEM quantitites) is a 
cost-effective, high-performance 
source of reliable data storage for 
small systems. BASF offers a variety 
of interfaces. BASF is also a supplier 
of disk and tape media. 

Century Data Systems, a Xerox 
Company, of Anaheim, California, 
offers a wide range of disk products 
for small systems including the 
14-inch Marksman model (Win- 
chester technology) with capacities 
from 10 to 30 megabytes, and the 
Hunter model with a removable 
16.7-megabyte 5440-type cartridge, 
plus fixed-disk capacity ranging from 
16.7 to 83.9 megabytes. Century 
Data Systems is a long-time manufac- 
turer of computer peripherals. 
Corvus Systems Inc, San Jose, 
California, is offering a complete 
hard-disk subsystem based on the IMI 
7710 10-megabyte 8-inch disk. It in- 
cludes the Z80-based Corvus in- 
telligent disk controller with com- 



prehensive diagnostics and interfaces 
for TRS-80, Apple II, S-100-bus, and 
LSI-11 computers. As mentioned 
above, Corvus also markets a 
100-megabyte removable backup in 
the form of an interface to a standard 
videocassette recorder using the 
microprocessor and interface bus of 
the Corvus disk subsystem. IMI was 
the first manufacturer to deliver a 
high-performance 8-inch Winchester 
drive. 

Memorex Corporation of Santa 
Clara, California, is introducing its 
first in a planned family of 8-inch 
hard-disk products, the Model 101. It 



offers low cost per megabyte, low 
weight (10 pounds), low power re- 
quirements (56 W), and high reliabili- 
ty. With 11.7 megabytes and 70 ms 
access time, it is a good example of a 
product in the low-end segment of the 
small hard-disk-drive market. 
Memorex has been manufacturing 
disk drives since 1967 and has been a 
major supplier of magnetic media 
since the company was formed in 
1961. The MSC-8000 from Micro- 
computer Systems Corporation of 
Sunnyvale, California, is an 8-inch 
disk drive with built-in removable 
backup in the form of an 80-mega- 



Call on John D. Owens for all Your Computer Needs 



GROUP PLANS AVAILABLE TO COMPUTER CLUBS 



COMPLETE PET BUSINESS PACKAGE 

31 fully integrated programs including Inventory, 
Sales summary, Accounts Receivable/payable, tax 
statements, general ledger, etc. etc. Prompts user. 
Validates each entry. Menu driven. Produced in 
London by G.W. Computers, Ltd. 

Users manual only (including postage) $7 

Complete package $750 

Complete listing only $300 

ATARI SUMMER SALE 

LIST PRICE SALE PRICE 

Computer, Model 800 $1,080 $845 

Disk Drive, Model 810 $ 699 $545 

Printer, Model 820 $ 599 $457 

Cassette, Model 410 $ 89 $75 

Paddle Controller Pair $ 19 $ 17 

MARINCHIP SYSTEMS M9900 

Elegant 16 bit CPU, S-100 compatible multi-user, 
multi-processor operating system. Extended precision 
commercial BASIC, FORTH, META, PASCAL, 
Word Processor and Text Editor. Fast and powerful! 

Complete kit and software package $550 

Assembled $750 

We configure complete systems with floppy or hard 
disk. 

WORDSMITH Video Subsystem $1,550 

S-100 Compatible, 40 lines, 80 columns. Powerful 
word processor and word processor keyboard. 

MICROANGELO $1,795 

High resolution graphics system. Wordsmith and 
Microangelo feature 15", 22MHZ, green phospher 
screen, 72 key keyboard; includes complete cabling 
and software. From SCION. 



INDUSTRIAL 

MICRO 

SYSTEMS 

TELETYPE 

HAZELTINE 

IBM 

TELEVIDEO 

TEI 

TARBELL 

SIEMENS 

PER SCI 

NEC 

ITHACA 

INTERSYSTEMS 

MARINCHIP 

DATA SOUTH 

QUME 
CENTRONICS 

TEXAS 

INSTRUMENTS 

ATARI 

DEC 

CALIFORNIA 

COMPUTER 

SYSTEMS 

KONAN 

EDGE 

TECHNOLOGY 

INNOTRONICS 

XEROX 

DIABLO 

INTEGRAL 

DATA SYSTEMS 

CROMEMCO 

SOROC 
MICROPRO 

TELETEK 

NOVATION 

FUJITSU 

CDC 

NORTH STAR 

COMMODORE 

SCION 

MPI 

POWER ONE 

MEASUREMENT 

SYSTEMS 
AND CONTROL 



SEE OUR AD AND ORDERING DETAILS ON FACING PAGE! 



JOHN D. OWENS 

212 448-6283 Associates, Inc. 212 448-6298 

12 Schubert Street, 

Staten Island, New York 10305 



August 1980 @ BYTE Publications Inc 145 



byte half-inch tape drive on the 
same motor spindle. Micropolis Cor- 
poration, of Chatsworth, California, 
is offering the largest capacity (now 
available) 8-inch Winchester disk, the 
Model 1203-1, with 45 megabytes on 
five surfaces. The density is high 
(8626 bpi, 478 tpi), the access time 
fast (42 ms), and the price reasonable. 
It is another good example of a high- 
capacity, high-performance 8-inch 
disk in the high-end segment. New 
World Computer Company Inc, of 
Costa Mesa, California, is making an 
unconventional, miniature hard disk, 
the Mikro-Disc 211. It is a cross be- 
tween a high-performance, one-head- 
per-track disk and a cost-effective 
moving head mini-Winchester drive. 
It is small, light (8 pounds), and very 
fast (18.825 ms access time). It has 
relatively low capacity (2.1 mega- 
bytes) but makes up for it in perfor- 
mance, price (less than $1000 in large 
OEM quantities), size (9Vz inch by 
9Vx inch), weight, and power re- 
quirements (less than 50 W). In the 
words of company president, Phil 



Haines, "It's a little screamer." The 
Mikro-Disc 211 is a versatile storage 
system suitable for a variety of uses: 
it can efficiently augment or replace 
floppy-disk drives, supplement other 
larger and slower mass-storage 
devices by acting as a high-speed 
cache memory, improve system 
response time by providing fast-ac- 
cess key-directory storage, and be the 
primary file device in small systems. 
It has an assembly with twenty pro- 
prietary low-cost heads that write 
and read data onto 0.008-inch-wide 
tracks. The head assembly is moved 
only seven 0.010-inch steps (eight 
positions) across the disk. Each step is 
accomplished in 5 ms, precisely and 
accurately, by a low-cost open-loop 
stepper motor. 

The Model 3450 from Priam, San 
Jose, California, is another example 
in the high-end segment, along with 
BASF and Micropolis. It has 34 mega- 
bytes on five surfaces, fast transfer 
rate (1.02 megabytes per second), and 
high density (6370 bpi, 480 tpi). It is a 
state-of-the-art product at a 



reasonable price. The Shugart 
Associates SAlOOO-series drives are 
another example of the low-end seg- 
ment along with the Memorex 101 
with 5- and 11-megabyte models. 

Shugart Technology of Scotts 
Valley, California (a new company 
not connected with Shugart 
Associates or Xerox) has just an- 
nounced its Model ST506 5-inch 
6-megabyte Winchester disk drive. It 
is the size of a 5-inch floppy drive and 
weighs only 3.5 pounds — 6 mega- 
bytes of reliable Winchester disk 
storage in the palm of your hand for 
$925 (OEM quantity 500)! In the 
popular parlance, this is a hot little 
product for the small computer 
system. Evaluation units are sched- 
uled to be available this month and 
production quantities by next month. 

The latest in disk drives for small 
systems are these 8-inch and 5-inch 
wonders. The hard disks are upon us, 
and they're taking personal com- 
puting forward by a giant step.B 



Directory of Hard-Disk Manufacturers 


BASF Systems 


Kennedy Company 


Pertec Computer Corporation 


OEM Peripheral Sales 


1600 South Shamrock Ave 


Peripherals Div 


Crosby Dr 


Monrovia CA 91016 


9610 De Soto Ave 


Bedford MA 01730 


(213) 357-8831 


Chatsworth CA 91311 


(617) 271-4000 


Memorex Corporation 


(213) 999-2020 


Century Data Systems Inc 


Recording Components Div 


Priam 


A Xerox Company 


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Microcomputer Systems Corporation 


Shugart Associates 


Corvus Systems Inc 


432 Lakeside Dr 


475 Oakmead Pky 


900 S Winchester Blvd 


Sunnyvale CA 94086 


Sunnyvale CA 94086 


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(408) 733-4200 


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(408) 246-0461 








Micropolis Corporation 


Shugart Technology 


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New World Computer Company Inc 




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Cupertino CA 95014 


(714) 556-9320 




(408) 446-9779 







146 August 1980 © BYTE Publications Inc 



DYNACOMP 



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16K BASIC runs on Cromemco computers 
Cursor addressing routines for Hazeltine, 
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provided along with disks 

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Circle 96 on inquiry card. 



BYTE August 1980 147 



NEECO 

PROUDLY 

INTRODUCES 



alto>)COMPUTERS 




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• Dual 8" floppy disks 

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CONTACT NEECO FOR ADDITIONAL INFORMATION ON 
HOW ALTOS CAN BECOME YOUR COMPUTER SOLUTION 



Altos computers range in price from less than $3000 to over $1 4,000. Altos Computer Systems' capabilities 
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ALTOS computers are distributed to Dealers/OEMs in the N.E. Region by MICROAMERICA 



Trial Tested Osborne Business Packages on the Superbrain 
• Accounts Receivable $250.00 Complete 4 Module 
CACTIAIADC • General Ledger $250.00 Package s 795 

WWB I VVHIIE • Accounts Payable $250.00 MicrosoftBASIC 

(Business Packages written in MicrosoftBASIC) • Payroll Package $250 00 s 325 



SUPERBRAIN 

32K RAM $2795 
64K RAM $2995 
FORTRAN $ 450 

The Superbrain is ideal for use as an intelligent 
terminal or stand alone microcomputer system for 
OEM's, commercial customers, and other • 

sophisticated computer users." 



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(regularly $350) 




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2 I/O Ports - one fully enabled RS232 
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Too many software packages are now 
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OEM/DEALER INQUIRIES 

All pricing and specifications are subject to change.l 



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02194 (617) 449-4310 



148 BYTE August 1980 



Circle 98 for NEECO 



Circle 99 for microamerica 




NEECO PROUDLY ANNOUNCES OUR 

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ON ALL CBM COMPUTERS! 



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The 8032 CBM Computer is now available! CBM™ 8000 SERIES BUSINESS COMPUTERS 



Ql commodore 




The new Commodore 8000 series computers offer a wide screen 
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capacity. The CBM 8050 supplies relative record files and 
automatic diskette initialization. It can copy all the files from one 
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32K RAM-Graphics Keyboard 
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32K RAM-80 Col.-4.0 O/S 
Friction Feed Printer 
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PRICE 



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Dual Drives 

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Drive Activity indicator lights 
Disk Operating System Firmware 

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Sequential file manipulation 
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PRODUCT DESCRIPTION 



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'Asterisks indicate summer delivery— all others are immediately available. 



SPECIAL OFFER ON CBM COMPATIBLE BUSINESS SOFTWARE! 

Purchasing software has always been difficult due to the "you buy it - you own it" attitude of most 
vendors. We at NEECO, recognize this problem and can now, on all of the Software Packages listed, offer 
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SOFTWARE 

Word Pro I 

Word Pro II 

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Word Pro IV 

BPI Integrated G/L 

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CMS G/L 

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*PET is a registered trademark of Commodore Business Machines. Small Keyboard PETS require a ROM Retrofit Kit. 

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All prices and specifications are subject to chanqe without notice. 



APPLICATION 


REOUIRES 


AUTHOR 


AVAILABILITY 


PRICE 


Word Processing 


8K + 


cassette 


Pro Micro 


Immediate 


$ 29.95 




10K 


+ 2040 








99.95 




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199.95 




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NEECO 

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NEEDHAM, MA 02194 



NEW ENGLAND ELECTRONICS CO., INC. 

"NEW ENGLAND'S Largest 

Computer Showroom" 



(617)449-1760 

MASTERCHARGE OR VISA ACCEPTED 
TELEX NUMBER 951021. NEECO 
MON-FRI, 9:00-5:30 



Circle 100 on inquiry card. 



BYTE August 1980 149 



Editor's Note 

We are particularly pleased to 
include this article by Dick and Jill 
Miller in this FORTH theme issue. 
One of the problems with past 
BYTE language issues has been the 
lack of concrete examples of the 
language being showcased — name- 
ly, a full, nontrivial program that 
does something useful or fun and, 
at the same time, shows an exam- 
ple of the language at its best. 

The program BREAKFORTH, 
written for the MMSFORTH 
language running on the Radio 
Shack TRS-80, does show the 
language FORTH at its best. This 
real-time video game, which is a 
version of the arcade-type game 
that requires the user to chip away 
at a "brick wall" by directing a 
bouncing ball at it with a paddle, is 
what Dick Miller calls "electronic 
flypaper" — a game so addictive 
that it keeps people trapped at 
their TRS-80, unable to stop play- 
ing. 

In addition to being playable 
(quite a testament to the speed of 
FORTH, especially if you have 
ever seen the same game written in 
TRS-80 BASIC), the game also 
gives an example of how a good 
FORTH program is put together, 



as well as how it can be more 
readable when properly written 
out with adequate indentation and 
comments. 

Another departure from 
previous language issues is the 
availability of the language 
FORTH at reasonable cost on a 
wide range of microcomputers (see 
chart of FORTH sources, 
elsewhere in this issue). Miller 
Microcomputer Services (MMS) 
supplies one of the most complete 
and well-supported versions of 
FORTH available, along with a 
newsletter and other FORTH pro- 
ducts available at reasonable 
prices. (For example, MMS sells a 
FORTH software package that 
adds floating-point arithmetic 
(both single- and 

double-precision) , complex 
arithmetic, and a full Z80 
assembler, all on floppy disk for 
$29.95.) 

This article was produced with 
the help of two other people not 
yet mentioned. The first is Tom 
Dowling, who wrote the 
MMSFORTH language for the 
TRS-80 and who does a large por- 
tion of the FORTH programming 
for MMS. The second person is 
Arnold Schaeffer, who wrote the 



BREAKFORTH program as his 
first FORTH program. If this 
achievement were not impressive 
enough, then I should add that 
Arnold is a high school student. 
This is proof that FORTH can be 
learned by anyone with sufficient 
enthusiasm for the language. 

Analyzing the BREAKFORTH 
program is a great way to learn 
about FORTH and how to pro- 
gram in it. The program can be 
typed in as is on a TRS-80 using 
MMSFORTH's full-screen editor 
and virtual memory, but I suggest 
that you first read John James' arti- 
cle in this issue, "What Is FORTH? 
A Tutorial Introduction, " before 
seriously studying the 
BREAKFORTH program. 

One final note on alteration: this 
program is meant to work on a 
TRS-80 Model I running 
MMSFORTH. Users of other 
FORTH systems having a graphic 
display of 48 by 128 resolution or 
better can probably get the pro- 
gram running by rewriting some 
words unfamiliar to their system. 
Some information designed to help 
in this conversion effort has been 
supplied in this article.... GW 



BREAKFORTH Into FORTH! 



A Richard Miller and Jill Miller 

Miller Microcomputer Services 

61 Lake Shore Rd 

Natick MA 01760 



About the Authors 

A Richard (Dick) and Jill Miller founded 
Miller Microcomputer Services in 1977 as a 
consulting firm specializing in support for the 
Radio Shack TRS-80. After continued 
dissatisfaction with other languages available 
for the TRS-80 (FORTRAN. COBOL, Pascal, 
PILOT, BASIC), they settled on FORTH as a 
language that combines the seemingly incom- 
patible traits of language complexity, high 
operating speed, and low memory overhead. 
They released their first version of 
MMSFORTH (version 1.5) in June 1979, and 
have been improving disk and cassette versions 
of the system ever since. MMSFORTH 
resembles the FORTH Inc version of the 
language called microFORTH, and was written 
independently with permission from that com- 
pany. 



Introduction to BREAKFORTH 

This BREAKFORTH program was 
created by Arnold Schaeffer. The 
program, which was purchased by 
MMS, has received minor modifica- 
tions and is now included with the 
purchase of MMSFORTH version 1.9 
(on a different range of blocks from 
those shown here, blocks 69 thru 74). 
We think it is a classic game as is, and 
fully expect individuals to modify it 
in accord with their game 
preferences — for their individual use. 

The BREAKFORTH program is a 
straightforward one, although it is 
not a trivial one. It combines many of 
the techniques of FORTH and can be 



followed easily with a little time and 
study. Figure 1 shows a typical 
BREAKFORTH video display, with 
an operator-controlled game paddle 
at the bottom, a bouncing ball, and a 
barrier to be knocked out one brick at 
a time by successive bounces until all 
the bricks have been cleared away. 
Each removed brick scores one point 
or more depending on its level, and 
there is a surprise bonus for a com- 
pletely cleared barrier. Ball speed and 
number of balls are selectable, but be 
warned that, as you bounce your way 
up to the higher layers, the ball speed 
increases! You might want to start 
with short games using five balls and 



150 August 1980 © BYTE Publications Inc 



NO FRILLS! NO GIMMICKS! JUST GREAT 

DISCOUNTS 

MAIL ORDER ONLY 




BYTE August 1980 151 



a ball speed of seven. Fifty balls and a 
speed of four will present a challenge 
for high scorers. 

BREAKFORTH offers some other 
features, too. As you and your 
friends try for better scores, a BEST 
score is kept to challenge your present 
effort. In addition, the paddle adds 
backspin in certain cases that we will 
leave you to discover. 

To add sound, plug an external 
speaker into the EAR jack of your 
cassette tape recorder, attach the mid- 
dle cable from the keyboard unit (not 
the motor remote cable) to the AUX 
jack of the tape recorder, and open 
the tape compartment door. While 
depressing the write-protect detector 
switch at the left side of the back of 
this compartment, simultaneously 
press the Record and Play keys. This 
procedure allows the cassette tape 
recorder to be used as an amplifier. 
The BREAKFORTH program 
manipulates the cassette port (nor- 
mally used for writing a program to 
tape), causing a sound to be amplified 
by the recorder and played on the 
speaker. 

Like other brands of electronic 
flypaper, BREAKFORTH may keep 
you glued to the keyboard. If you 
have to leave but do not want to give 
up the game, press shift-® to pause 
the game. Pressing any other key will 
cause the game to resume where you 



BREAKFORTH is 
developed in the FORTH 
manner, with top-down 
design and bottom-up pro- 
gramming. 



left off. To start a new game in 
midstream while keeping the BEST 
score, press the Break key, type in the 
word BREAKFORTH , and press the 
Enter (Return) key. 

BREAKFORTH is developed in the 
FORTH manner, with top-down 
design and bottom-up programming. 
Figure 2 shows the organization of the 
program. These modules shown in 
figure 2, along with the various 
1-byte and single-precision (2-byte) 
variables and constants they invoke, 
are listed with explanations in table 1, 
a directory of the BREAKFORTH 
words that this program will add to 
the FORTH vocabulary. 

The program's source code is on six 
consecutive blocks, and in this case 
happens to be located on blocks 50 
thru 55; see listing 1. In 
MMSFORTH, one enters 
j 50 6 LOADS j to load the pro- 
gram — that is, to compile and execute 
all the information on blocks 50 thru 



BREAKFORTH IN MMSFORTH 



SCORE: 253 BEST. 





Figure 1: One view of the TR.S-80 video screen during a BREAKFORTH game. 



55, ending with the immediate execu- 
tion of the word BREAKFORTH 
from line 15 of block 55 (which causes 
the program to be run). (Other ver- 
sions of FORTH that lack the 
consecutive-blocks word, LOADS , 
will have another way of doing this.) 

The First Block 

Let us take a detailed look at block 
50 in listing 1. Lines thru 2 are all 
comment lines, as are any words sur- 
rounded by parentheses. Notice that 
because FORTH words are set off by 
spaces on either side, the "begin com- 
ment" word, j ( | , must be 
separated from the first word of the 
comment by at least one space. 
(Because of the way j ( } is defined, 
the closing parenthesis need not be 
separated from the last word of the 
comment by a space.) 

Most definitions in FORTH begin 
with a colon ( { : j ) and end with a 
semicolon ( j ; j ), where the first 
word after the colon is the word being 
defined. In line 3, the first word de- 
fined is TASK . Since the only word 
following TASK is the closing 
semicolon, we can conclude that the 
word TASK does not do much. 
However, it does serve as a 
"bookmark," marking the beginning 
of the words and variables that are 
specific to this application (game). 
We will come back to TASK later, at 
the end of block 55. 

Line 3 also causes two other blocks 
on the MMSFORTH system disk to 
be loaded into memory. Block 32, 
when loaded, adds several special- 
purpose words having to do with 
random numbers: RANDOMIZE 
and RND . Block 33, when loaded, 
adds several words that have to do 
with graphics: DCLR , DSET , 
{ D? } , ECLR , ESET , and 
{ E? } . (The last three are the same 
as TRS-80 BASIC words RESET, 
SET, and POINT, and the variables 
beginning with D are the same, but 
referencing double-width characters.) 

Lines 4 thru 6 initialize seven 
double-byte variables and two single- 
byte ( CVARIABLE ) variables. In 
FORTH, unless specified, all 
variables, constants, and stack entries 
are 16 bits (2 bytes) long. See table 1 
for the meaning of these variables. 

Line 7 defines a new word, LINE , 
using a colon to begin the definition 
and a semicolon to end it. Several 
spaces (usually three) are placed be- 



152 August 1980 © BYTE Publications Inc 



THE NEXT GENERATION OF MICROCOMPUTERS IS HERE 

AT QUASAR DATA PRODUCTS 




16 BIT POWER 

Z-8000 



AND STILL RUN YOUR 8 BIT SOFTWARE 



IF YOU SEE IT OUR WAY THEN WE THINK WE 
HAVE THE PRODUCTS FOR YOU: 

• THE S-100 BUS IS HERE TO STAY. IT IS NOT THE GREATEST BUT 
WITH PROPER TERMINATION IT WORKS RELIABLY AT HIGH SPEEDS, 
AND SINCE IT IS NOW AN IEEE STANDARD, IT IS WELL DEFINED. 

• THE 8 BIT SYSTEMS ARE USEFUL BUT THEY ARE THE LIMITING 
FACTOR FOR MANY APPLICATIONS. 

• THE 16 BIT SYSTEMS ARE THE WAY FUTURE SYSTEMS WILL GO. 
WHY NOT? THERE IS VERY LITTLE PRICE DIFFERENCE AND AN 
ORDER OF MAGNITUDE PERFORMANCE DIFFERENCE. 

• THE REAL USEFULNESS OF THE 16 BIT MICROPROCESSORS WILL 
BE DETERMINED BY THE SOFTWARE. 

• THE SYSTEMS USING SV, INCH DISK DRIVES REALLY DO NOT HAVE 
ADEQUATE MEMORY STORAGE OR COMPUTER POWER FOR MANY 
BUSINESS OR SCIENTIFIC APPLICATIONS. 

• SIXTY-FOUR KILOBYTES OF ADDRESSABLE RAM, THE MAXIMUM 
FOR 8 BIT SYSTEMS. IS NOT ADEQUATE FOR MANY BUSINESS OR 
SCIENTIFIC APPLICATIONS. 

• IT IS NOT WORTH BUYING 8 BIT SYSTEMS OR BOARDS NOW IF YOU 
CAN GET THE SAME SOFTWARE WITH 16 BIT SYSTEMS AT ABOUT 
THE SAME PRICE. 

Z-8000 SERIES 16 BIT CPU S-100 BOARD — CAN BE PLUGGED 

• FULLY S-100 IEEE COMPATIBLE 

• SUPPORTS EXISTING 8 BIT MEMORY AND 8 BIT 
PERIPHERAL BOARDS 

• CAPABLE OF READING AND/OR WRITING 8 BIT, 16 BIT 




INDUSTRIAL 
QUALITY 



OR MIXED 8 BIT AND 16 BIT MEMORIES AUTOMATICALLY 

8 BIT AND/OR 16 BIT PERIPHERAL MODULES CAN 

SIMULTANEOUSLY CO-EXIST IN THE SAME BUS WITHOUT 

ANY MODIFICATIONS 

CAPABLE OF OPERATING AS A SLAVE PROCESSOR TO ENABLE 

YOUR EXISTING CPU TO CONTROL THE Z-8000 



QDP-8100 WITH 2 MEGABYTES STORAGE 
STANDARD (OPTIONAL 4 MEGABYTES) 

• Z-8000 SERIES 16 BIT CPU S-100 BOARD - SEE ABOVE 

• SOFTWARE (PROVIDED WITH SYSTEM) 

• CP/M 2.2' OPERATING SYSTEM . _ __ 

• basic $6,395. 



SYSTEMS 



• THE NEW 16 BIT MICROPROCESSORS HAVE POWER COMPARABLE 
TO MINICOMPUTERS BUT DO NOT REQUIRE THE SAME OVERHEAD 
IN TERMS OF DOWNTIME. MAINTENANCE. OR INITIAL INVESTMENT 
THEY ARE MORE VERSATILE IN MANY APPLICATIONS SUCH AS 
REAL TIME APPLICATIONS. 

THIS IS WHAT QDP HAS AVAILABLE: 

• A Z-8000 BOARD THT CAN PLUG INTO YOUR EXISTING S-100 BUS 
SYSTEM (SEE BELOW FOR DESCRIPTION) 

• A COMPLETE Z-8000 SYSTEM (SEE BELOW FOR DESCRIPTION) 

• A Z-8000 SYSTEM CONFIGURED FOR YOUR EXACT NEEDS. 

• SOFTWARE TO ALLOW YOU TO RUN ALL THE AVAILABLE Z-80/8080 
SOFTWARE INCLUDING CP/M 

• SOFTWARE THAT INCLUDES A MONITOR. DEBUGGER. 
DISASSEMBLER. AND BASIC 

• SOFTWARE OPTIONS A) EXTENDED MONITOR B) PASCAL 

C) SIMULATORS FOR 8080. Z-80, 6800. 6502. 1802 

• A Z-80 SYSTEM (QDP-100) THAT IS UPWARD COMPATIBLE WITH 
THE Z-8000 

THIS IS WHAT IS COMING FROM QDP: 

• A 256 KILOBYTE RAM CARD. • UNIX 2 OPERATING SYSTEM. 

INTO YOUR EXISTING SYSTEM $695.00 

SUPPORTS ONBOARD HARDWARE SINGLE STEPPING 

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POWER-ON AND RESET JUMP DIP SWITCH SELECTABLE 

JUMPER SELECTABLE 2 OR 4 MHz. OPERATION 

DIP SWITCH SELECTABLE NUMBER AND TYPE OF WAIT STATES 

SOFTWARE 

• Z-80 EMULATOR ENABLES YOU TO EXECUTE YOUR EXISTING 
8 BIT SOFTWARE WITHOUT ANY MODIFICATIONS AND 
ALLOWS YOU TO RUN CP/M IMMEDIATELY 

• EXTENDED MONITOR, DEBUGGER, DISASSEMBLER 

QDP-100 WITH 2 MEGABYTES STORAGE 
STANDARD (OPTIONAL 4 MEGABYTES) 

• Z-80 SERIES 8 BIT CPU S-100 BOARD (4 MHZ Z-80, DBLDENSITY 
DISK CONTROLLER. 2716 PROM BURNER 2 PARALLEL & 2 SERIAL 
PORTS. REALTIME CLOCK) A . «m»— ■ 

• SOFTWARE (PROVIDED WITH SYSTEM) $4,995. 



Z80/8080 EMULATOR 
MONITOR, DEBUGGER, DISASSEMBLER 
SOFTWARE OPTIONS: PASCAL 
UNIX 2 OPERATING SYSTEM COMING 

• INTELLIGENT CRT TERMINAL (80 CHARACTERS X 24 LINES) 

• 64 KBYTES RAM 

• TWO 8 INCH, DOUBLE SIDED, DOUBLE DENSITY FLOPPY DISK DRIVES WITH CONTROLLER 

• 2 SERIAL AND 1 PARALLEL (2 PARALLEL FOR QDP-100) PORTS 

• ATTRACTIVE WOODGRAIN CABINET WITH POWER SUPPLIES AND CABLING 
FULL TECHNICAL SUPPORT FROM THE STAFF AT QUASAR DATA PRODUCTS 



EACH SYSTEM 
CONTAINS: 

ICP/M™ DIGIJAL RESEARCH 
•UNIX'" BELL LABS 



CP/M 2.2' OPERATING SYSTEM 

BASIC 

ACCOUNTS RECEIVABLE, GENERAL LEDGER, ACCOUNTS 

PAYABLE, PAYROLL WITH COST ACCOUNTING 

OPTIONAL SOFTWARE: FORTRAN, PASCAL, COBOL, C 



DP 



4 Mhz 64K Dynamic RAM 

16K - s 250°° 32K - s 350°° 48K - s 450 ' 



TELETEK DBL. DENSITY, DBL. SIDED 



64K - 5 549 01 



Disk Controller Board. 



s 395 ' 



QUASAR FLOPPY SYSTEM 

• Two MFE DBL sided drives • Cable • Case & Power Supply 
assembled and tested vV ooc j cabinet s 1895°° 

QUASAR 2 MEG FLOPPY 

• 2 MFE double sided drives 

• Teletek disk controller board 

• Power supply & cable 

• Wood cabinet 

• CP/M version 2.2 & bios 
Assembled & tested s 2295°° 

Dealer Inquiries Invited, Hours:9-5:30 M-F 

Specifications Subject To Change 
UnixTM - Bell Lab 30 Day ARO CP/Mtm - Digital Research 





PAPER TIGER 

Includes Graphics s 949° 

Cable for TRS-80 s 39° 

Call for Apple 



MFE Double Sided - Double Density 

Floppy Disk Drives, (the best) 650°° 

Using the Teletek Controller under CP/M, 
THIS DRIVE WILL GIVE YOU ALMOST 
ONE MEGABYTE PER DISK DRIVE. 
Power supply for above "110°° 



TI - 820 

Serial Printer - 
Full package options. . . '1995° 




Checks, money orders accepted 
Add $2.50 freight charges on orders under 10 lbs. Over 10 lbs. F.O.B. Cleveland 

QUASAR DATA PRODUCTS 

25151 Mitchell Dr., No.Olmsted, Ohio 44070 (216)779-9387 



1 


VISA" 







Circle 102 on inquiry card. 



BYTE August 1980 153 



Circle 103 on inquiry card. 



MORE FOR YOUR 

RADIO SHACK TRS-80 

MODEL I ! 



• MORE SPEED 

10-20 times faster than Level II BASIC. 

• MORE ROOM 

Compiled code plus VIRTUAL 
MEMORY makes your RAM act larger. 

• MORE INSTRUCTIONS 

Add YOUR commands to its large in- 
struction set! 

Far more complete than most Forths: 
single & double precision, arrays, 
string-handling, more. 

•k MORE EASE 

Excellent full-screen Editor, structured 
& modular programming 
Optimized for your TRS-80 with 
keyboard repeats, upper/lower case 
display driver, single- & double-width 
graphics, etc. 

• MORE POWER 

Forth operating system 
Interpreter AND compiler 
Internal 8080 Assembler (Z80 
Assembler also available) 
VIRTUAL I/O for video and printer, 
disk and tape (10-Megabyte hard disk 
available) 




FORTH 



THE PROFESSIONAL FORTH 
FOR TRS-80 

Prices: 

MMSFORTH Disk System V1.9 (requires 1 

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MMSFORTH Cassette System V1.8 (requires 
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AND MMS GIVES IT 
PROFESSIONAL SUPPORT 

Source code provided 
MMSFORTH Newsletter 
Programming staff available 
Many demo programs aboard 
MMSFORTH User Groups 

FLOATING POINT MATH (L.2 BASIC ROM 
routines plus Complex numbers, 
Rectangular-Polar coordinate conversions, 
Degrees mode, more), plus a full Z80 
ASSEMBLER; all on one diskette . . . $29.95* 
THE DATAHANDLER, a very sophisticated 
database management system operable by 
non-programmers (requires 1 drive and 32K 
RAM); with manuals $59.95* 

Other packages under development 

FORTH BOOKS AVAILABLE 

MICROFORTH PRIMER — comes with 

MMSFORTH; separately $15.00* 

USING FORTH — more detailed and advanc- 
ed than above $25.00* 

URTH TUTORIAL MANUAL — very readable 

intro. to U/Rochester Forth $19.95* 

CALTECH FORTH MANUAL — good on 
Forth internal structure, etc $6.95* 

* — Software prices are for single-system 
user license and include manuals. Add $2.00 
S/H plus $1.00 per additional book; Mass. 
orders add 5% tax. Foreign orders add 15%. 
UPS COD, VISA & M/C accepted; no unpaid 
purchase orders, please. 

Send SASE for free MMSFORTH information. 
Good dealers sought. 

MMSFORTH is available from your 
computer dealer or 

MILLER MICROCOMPUTER 
SERVICES (B1) 

61 Lake Shore Road, Natick, MA 01760 
(617)653-6136 



BREAKFORTH 




PADDLE 




GAMECHK 



BALLCHK 



XCHK 



CLR 



BOP 



1CASSOUT 



2CASSOUT 



Figure 2: A hierarchical diagram of the BREAKFORTH program. Each box contains a 
word used within the BREAKFORTH program and is used by the word(s) in the box(es) 
above it. See table 1 for a definition of each word. 



tween the word being defined and the 
first word of the definition; this adds 
to the clarity of the definition. PTC 
(for "put cursor") places the cursor at 
a given point on the screen, much like 
the PRINT® instruction in TRS-80 
BASIC. It expects two numbers on 
the stack, the row (second-to-top) 
and the column (on top) giving the 
desired position for the cursor. (For 
example, j 8 32 PTC 1 puts the 
cursor near the center of the screen, 8 
rows from the top and 32 characters 
from the left edge of the screen.) 

However, our new word LINE ex- 
pects only one number on the stack 
because the first thing it does when it 
is called is to put a zero on top of the 
stack. So the words f PTC ) put 
the cursor at the beginning of a given 
line (that is, at position (x,0), where x 
is the number on top of the stack 
when LINE is called). 

The FORTH word ECHO (EMIT in 
some other versions of FORTH) is 
like the PRINT CHR$ function in 
BASIC — it outputs the correspon- 
ding ASCII character for the number. 
In this case, ( 30 ECHO ) outputs a 



clear-to-the-end-of-the-line signal on 
the TRS-80. (By the way, the 30 is the 
decimal number thirty; although you 
can change to hexadecimal with the 
word HEX or to any other numeric 
base, MMSFORTH assumes decimal 
numbers unless told otherwise.) 

Now we are finally able to say 
what the word LINE does: the 
phrase { x LINE j clears line x and 
leaves the cursor at row x, column 0. 
{ PTC j puts the cursor at the 
beginning of the line, and 
( 30 ECHO j clears the line with a 
special character (ASCII decimal 30) 
and leaves the cursor where it is. 

The final word described in block 
50, INIT , begins in line 8. Its defini- 
tion is longer than most words, but its 
function is not at all mysterious once 
you know a few FORTH words. CLS 
clears the video screen (as in TRS-80 
BASIC), ( LINE j clears line zero, 
and { " j (( ". J in some FORTHs) 
causes the character string until the 
next quote mark to be printed, just as 
PRINT " STRING " does in BASIC. 
The word #IN causes a single- 

Text continued on page 158 



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OMEGA OFFERS THE BEST DELIVERY AND PRICE ON: 
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YOU TOO can 
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ENTREPRENEUR! 



«> s 



HOW TO START YOUR OWN SYSTEMS 
HOUSE is a practical step-by-step guide for the 
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Written by the founder of a successful systems 
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Proven, field-tested solutions to the many 
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presented. 

From the contents: 

• New Generation of Systems Houses • The 
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tion /Plans of Major Vendors • Market 
Segment Selection & Evaluation • Selection of 
Equipment & Manufacturer • Make or Buy 
Decision • Becoming a Distributor • Getting 
Your Advertising Dollar's Worth • Your Sales- 
men: Where to Find Them • Product Pricing 

• The Selling Cycle • Handling the 12 Most 
Frequent Objections Raised by Prospects • 
Financing for the Customer • Leasing • 
Questions You Will Have to Answer Before the 
Prospect Buys • Producing the System • In- 
stallation, Acceptance, Collection • Docu- 
mentation • Solutions to the Service Problem 

• Protecting Your Product • Should You Start 
Now? • How to Write a Good Business Plan • 
Raising Capital 



6th edition, March 1980 



220 pages 



Address 

City 

State 



.Z'P_ 



Essex Publishing Co. dept. 3 

285 Bloomfield Avenue Caldwell, N.J. 07006 

I would like to order HOW TO START YOUR 
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For immediate shipment on credit card orders 
call (201) 783-6940 



Listing 1: The BREAKFORTH program. These six blocks, when loaded into an 
MMSFORTH system, cause the BREAKFORTH program to compile, execute, and, 
once finished, erase itself from the system. Tape-based users should omit the last three 
words in the last block. This program does require that the MMSFORTH words for ran- 
dom numbers (block 32 on the MMSFORTH system disk or cassette) and for TRS-80 
graphics (block 33) be available to the FORTH system. If these blocks have already been 
loaded, delete the two LOAD commands in block 50, line 3. Also, the se- 
quence | A MVI 255 ) in lines 10 and 11 of block 51 is the notation FORTH uses for 
the 8080 assembly-language statement MVI A, 255. [To speed up paddle response, 
you can replace the 3 in block 55, line 8 with a higher value. Personally, I enjoy playing 
the game at speed level 1, with a 12 replacing the 3....GW] 



BLOCK 



50 



( BREAKFORTH/MMSFORTH, BY ARNOLD SCHAEFFER, PART 1 OF 6 ) 

1 ( COPYRIGHT 1980 BY MILLER MICROCOMPUTER SERVICES ) 

2 ( W/SOUND - USE THE LEFT AND RIGHT ARROWS TO MOVE THE PADDLE ) 

3 : TASK ; 32 LOAD ( RANDOM #'S ) 33 LOAD ( GRAPHICS ) RANDOMIZE 

4 CVARIABLE SPEED CVARIABLE SPVAR VARIABLE SCORE 

5 VARIABLE XPOS VARIABLE YPOS 2 VARIABLE PPOS 

6 1 VARIABLE YDIR 1 VARIABLE XDIR VARIABLE BEST 

7 : LINE PTC 3 ECHO ; 

8 : INIT CLS LINE " SPEED ( 1 - 10, 1 IS FASTEST )" 

9 #IN 1 MAX 10 MIN 10 U* SPEED C! 

10 LIME " NUMBER OF BALLS DESIRED" #IN 

11 CLS 64 DO 3 I DSET 4 I DSET LOOP 

12 48 3 DO I DSET I 63 DSET I 1 DSET I 62 DSET LOOP 

13 191 15616 320 FILL SCORE ! 

14 LINE " BREAKFORTH IN MMSFORTH SCORE: BEST:" 

15 BEST ? 54 PTC " BALL:" ; 



BLOCK 



51 



( BREAKFORTH/MMSFORTH, BY ARNOLD SCHAEFFER, PART 2 OF 6 ) 

: PCLR 32 PPOS 8 16320 + 8 FILL ; 
: PSET 176 PPOS @ 16320 + 8 FILL ; 





1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 



BLOCK : 52 



PADDLE 
14400 C@ 32 
14400 C@ 64 



CODE 1CASSOUT 
CODE 2 CAS SOU T 
: BOP 10 DO 



IF PCLR 
IF PCLR 



-1 PPOS @ + 2 MAX PPOS ! PSET THEN 
1 PPOS @ + 54 MIN PPOS ! PSET THEN 



1 A MVI 255 OUT NEXT ( THESE 3 LINES ) 

2 A MVI 255 OUT NEXT ( PRODUCE THE SOUND. ) 
1CASSOUT 2CASSOUT LOOP ; 



( BREAKFORTH/MMSFORTH, BY ARNOLD SCHAEFFER, PART 3 OF 6 



XCHK 

XPOS @ 2 < 

XPOS @ 61 > 



IF XDIR @ MINUS XDIR 
IF XDIR @ MINUS XDIR 



2 XPOS ! 
61 XPOS ! 



BOP THEN 
BOP THEN 



BOP THEN 





1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 



BLOCK : 53 

( BREAKFORTH/MMSFORTH, BY ARNOLD SCHAEFFER, PART 4 OF 6 ) 
1 

Listing 1 continued on page 158 



YCHK 
YPOS 
YPOS 
YPOS 
YPOS 



5 
23 
19 

15 



IF 1 YDIR ! 

IF SPVAR C@ 

IF SPVAR C@ 

IF SPVAR C@ 



5 YPOS ! 1 SPVAR C! 
4 MIN SPVAR C! THEN 
3 MIN SPVAR C! THEN 
2 MIN SPVAR C! THEN 



156 August 1980 @ BYTE Publications Inc 



=° -«2 n m 9 B 




FORTH 

FORTH GENERATION SOFTWARE 

ConcurrentFORTH 64 users/CPU 

Data General and cornpatable systems 

Digital Equipt Corp PDP 11, LSI 11 VAX 11-780 

IBM Series 1 Texas Instrument 990 



Custom Systems Professional/Commercial/OEM 

1802 6502 6800 6809 68000 8080 8085 
Z80 28 Z8000 TI9900 micronova HP21 

Systems level software 

File Systems 
Data base management 
Non-procedural query languages 
Word processing Office Automation 
Industrial Control 

Send RFP with your requirements to; 



fl 



NCON 



17370 Hawkins Lane 
Morgan Hill, CA 95037 

Circle 106 on inquiry card. 
PUBLICSERVICE ANNOUNCEMENT 
For general information join FORTH interest group $12.00 to; P.O. Box 
1105, San Carlos, CA 94070. Source code for popular micros $10.00, 
installation manual $10.00, Programming manual "Using FORTH" $25.00. 
No purchase orders. Circle 311 on inquiry card. 



The 2nd 
Generation... 

It's all that it's 
Cracked up to be. 




MEASUREMENT 

systems & controls 

incorporated 



BYTE August 1980 157 



Text continued from page 154: 

precision number to be entered from 
the keyboard and placed on top of the 
stack. The phrase 

( 1 MAX j causes the number to 
be replaced by 1 if the number just 
entered is smaller. Similarly, the 
phrase ( 10 MIN ) limits the 
number on the top of the stack to a 
maximum value of 10. 
( 10 U* j multiplies the number by 
10 ( U* is an unsigned single- 
precision multiply), and 
/ SPEED C! j stores the value 
from the top of the stack in the 
single-byte variable SPEED . 

Each of the above phrases contains 
a number and an operation. Since 
each operation requires two numbers 
on the stack, the number entered by 
#IN is the first number, with the se- 
cond number always being supplied 
by the first word of the phrase. 

Using the same words as listed 
above, line 10 again clears line 0, 
prompts for the number of balls to be 
used in the game, putting that 
number on top of the stack with the 
word #IN . 

Line 11 clears the video screen 
again and sets up the back (top) wall 
of the BREAKFORTH "court" using a 
do-loop and double-width graphics. 
In FORTH, the parameters of the 
loop go on the stack before the loop is 
called, so j 64 DO ) begins the 
loop, and the word LOOP ends it. 
The loop will be executed sixty-four 
times, and the word I puts on top-of- 
stack the current value of the loop (0, 
1, 2, 3, ... ,63); note that I does not 
take on the limit value of 64. The 
phrase ( 3 I DSET j sets a double- 
width character at row 3, (double- 
width) column I; similarly, 
f 4 I DSET j sets the double-width 
character on the next row below the 
first. 

Similarly, line 11 sets the right and 
left walls of the BREAKFORTH 
court, columns and 1 for the left 
wall and columns 63 and 64 for the 
right wall. 

The phrase ( 191 15616 

320 FILL ) in line 13 creates the ini- 
tial wall of bricks by using character 
code decimal 191 (a whited-out 
character cell) to fill an area of 
memory (the video display area of the 
TRS-80) starting at location 15616 
and filling for a total of 320 bytes. 

The phrase ( SCORE ! } , also 
in line 13, shows us how we store a 



Listing 1 continued: 



2 2 

3 

4 : 

5 

6 

7 

8 

9 
10 
11 

12 ; 
13 
14 
15 



BLOCK 



CONSTANT 2 



-2 CONSTANT 



PCHK YPOS I 47 >= 

IF 46 YPOS ! XPOS @ PPOS § 



IF -1 YDIR ! 
NCASE 12 
XDIR ! 
ELSE DROP 1+ 
THEN 
THEN 



BOP 
3 4 5 6 7 



DUP >= OVER 8 < AND 
-2-1-1-11112 CASEND 



54 



( BREAKFORTH/MMSFORTH, BY ARNOLD SCHAEFFER, PART 5 OF 6 ) 
1 

CLR 

XPOS 8 2 - 12 4 AND 2+ DUP 4 + SWAP DO YPOS 8 I DCLR LOOP 

YPOS 8 27 - ABS SCORE +! 32 PTC SCORE ? BOP 

YDIR 8 MINOS YDIR ! 



BALLCHK 



9 
10 
11 
12 
13 
14 
15 



YDIR @ YPOS +! XDIR 8 XPOS +! 
YPOS 8 XPOS 8 D? IF CLR THEN 



XCHK YCHK PCHK 



BALL YPOS 8 XPOS @ DCLR 

BALLCHK DUP 0= IF YPOS @ XPOS 8 DSET THEN ; 

GAMECHK SCORE 8 1800 MOD 0= IF 191 15616 320 FILL THEN 



BLOCK : 55 



( 

1 : 

2 : 
3 

4 
5 
6 
7 



BREAKFORTH/MMSFORTH, BY ARNOLD SCHAEFFER, PART 6 OF 6 ) 
DELAY SPEED C8 SPVAR C8 U* DO LOOP ; 
BREAKFORTH 
BEGIN INIT 



9 

10 
11 
12 
13 

14 ; 

15 BREAKFORTH 



ELSE -1 THEN 
! 29 YPOS ! 
DO PADDLE LOOP 
GAMECHK DELAY 



DELAY PADDLE LOOP 
5 SPVAR C! 

XDIR ! 



PSET 
DO 2000 SPEED C8 / DO 

60 PTC I 1+ 

2 RND 1 = IF 1 

58 RND 2+ XPOS 

BEGIN 3 
BALL 

END 
LOOP SCORE 8 BEST 8 MAX BEST ! 
8 18 PTC " RUN GAME AGAIN " Y/N 



1 YDIR ! 



END 



FORGET TASK DIR 



value (0) in a variable ( SCORE ) by 
using the store operator ( ! j . Two 
points should be mentioned here. 
First, executing a variable name (like 
SCORE ) causes the address of the 
variable, not its value, to be pushed 
onto the top of the stack. Second, the 
store operator ( ! j requires the value 
to be the second-to-top item in the 
stack and the address of the variable 
receiving the new value to be the top 
item in the stack. 

The words in line 14 clear line 
and print a message on the same line, 
setting the score to zero but leaving 
the cursor just after the colon that 



ends the message. 

In line 15, the phrase 
( BEST ? j causes the value of 
BEST to be displayed on the screen, 
and the rest of line 15 completes the 
message that is shown on line of the 
screen. Finally, the semicolon on line 
15 ends the definition of INIT begun 
on line 8. 

The Middle Blocks 

Whew, that was a lot of explaining! 
Now you see why FORTH is not very 
easy for beginners to read — you are 
packing a lot of work into a small 
space, using an ever-more-specialized 



158 August 1980 © BYTE Publications Inc 



... i 






You Knew 
Tarbell 




But, do you know oil the co 



Torbell has ready for you? 



When someone says "Tarbell" there's 
no cloubr what's meant . . . the cas- 
sette interface whose reliability and 
solid engineering mode it an in- 
dustry standard. 

Since that first breakthrough- 
product, Don Tarbell has expanded 
his list of useful, dependable com- 
ponents . . . components to meet 
your needs of today, and keep you 
prepared for tomorrow. 

Check this partial list of quality com- 
ponents Don Tarbell has ready for 
you. You're probably ready for 
them, right now. 

• When it comes to RAM memory, 
Tarbell means reliability. 16K and 
32K static memory that offers you 
easier trouble shooting, and far 
eosier maintenance. Remember 
that. 



• Tarbell QASIC'tfW! Simplicity and 
sophistication to your programs. Our 
BASIC is easier to program, and offers 
unique commands and statements 
not found in regular BASICS under 
any name. 

• CP/M® disk operating system is, 
of course, the standard for software 
exchange. At Tarbell we provide our; 
own approved CP/M system mod- 
ified for all Tarbell floppy disk inter- 
faces. Note. We also hove MP/M® for 
those interested in mulfi user systems. 

• The Tarbell VDS line comes as a 
complete package . . . or, as sep- 
arate units. For example, the Tarbell 
mainframe can be ordered with 1 
or 2 Shugart or Siemens drives, or 
no drives. Whichever way you go, 
you get the reliability of Tarbell 
rested components. 



With the Tarbell Double Density 
floppy disk interface, storage capa- 
city, speed and versatility are greatly 
increased. Under our DD CP/M, single 
and double density disks may be 
intermixed with no penalty. The 
system automatically determines 
which is in place. 

We also still have our Single Density 
floppy disk interface. It's specifically 
designed to operate with many dif- 
ferent and unusual drives. Naturally, 
they're Tarbell tested. 




950 Dovlen Place, Suite B 
Carson; California 90746 
(213)508-4251 / 538-2254 

*CP/M & MP/M ore products of Digital Research Corp. 



Circle 107 on inquiry card. 



BYTE August 1980 159 



f BEGIN J 



START GAME OVER 
AGAIN, RETAINING 
ONLY VALUE OF 
BEST 



ALL BALLS HAVE 
BEEN PLAYED; 
CURRENT GAME 
IS OVER 



T 
A 



YES 



BEST " MAX 
(SCORE, BEST) 




12 



PUT ON 
TOP-OF-STACK 



THIS IS A DO-LOOP 
BEGINNING AND ENDING 
ON LINE 4; BEGINNING 
VALUE IS ZERO, ENDING 
VALUE IS (X* - 1) 



PUT 1 ON 
TOP-OF-STACK 



YES 




TEST OF 


LOOP 


BEGINNING 


AT LINE 


3; TEST 


IS 


"DID 


PLAYER 


PRESS 'Y' 


KEY?" 








5 




PRINT BALL 
NUMBER (=1+1) 
AT (0, 60) 


5 




SPVAR = 5 


6 




R* = RND (2) 



f FINISH J 



Figure 3: A flowchart for the BREAKFORTH program (given in listing 1, block 55). The number above each box is the line 
number within block 55 that performs the action of the box. Many calculations in FORTH are done on the stack and do not acquire 
variable names. Because of this, an asterisk in a variable or procedure name (eg: X*, 3PADDLE*) denotes that the name was given 
only in this flowchart to add clarity. 



instruction set. Experience with 
reading and writing FORTH code 
makes the process easier, but spacing, 
indentation, use of descriptive word 
names, and lots of comments are 
always helpful. A surprise to the 
BASIC user: none of these source- 



code editing improvements use any 
extra programmable memory space. 
Table 1 explains much of what the 
words in blocks 51 thru 54 do, but let 
us look at some of the interesting 
features contained in these lines of 
FORTH code. 



When the ten-to-twenty times 
speed increase of FORTH over 
BASIC is not enough (or when we 
want to do things that cannot be done 
with existing FORTH words), we can 
redefine some FORTH words in the 
assembly language of the computer 



160 August 1980 © BYTE Publications Inc 




PUT 1 ON 
TOP-OF-STACK 



PUT -1 ON 
TOP-OF-STACK 



XDIR'TOP-OF-STACK 
YDIR «1 



XPOS-RND (581+2 
YPOS=29 



BEGIN LOOP AT LINE 8, 
TEST AT LINE 10 



3PAODLE * 



PADDLE IS PERFORMED 
3 TIMES WITHIN SHORT 
DO-LOOP 



MOVE BALL TO NEW 
CALCULATED POSITION 



CHECKS TO SEE IF 
BALL HAS GOTTEN PAST 
PADDLE-, IF SO, PUTS 1 
ON TOP-OF- STACK; 
ELSE PUTS 0(IF BALL 
STILL IN PLAY) 



GAMECHK 



IF WALL IS COMPLETELY 
GONE, DRAWS NEW 
WALL 



DELAY 



NO 




TEST OF LOOP AT 
BEGINNING OF LINE 8; 
TEST IS: "HAS BALL 
GOTTEN PAST PADDLE?" 



NBP* =NBP * +1 
(INCREMENT NUMBER 
OF BALLS PLAYED 



THIS IS END OF 
DO-LOOP BEGUN AT LINE 
4-, GO TO BEGINNING OF 
LOOP FOR LIMIT TEST 



(in the case of the TRS-80, 8080 or 
Z80 assembly language). When we 
want a FORTH word (program) to 
run faster, usually a short assembly- 
language definition of the word that 
gets used the most will speed things 
up sufficiently. Lines 10 and 11 of 
block 51 are the only two words used 
in BREAKFORTH that are defined in 
8080 assembly language. 



(MMSFORTH comes with a com- 
pact 8080 assembler built in, like 
many Z80-based FORTHs. A full Z80 
assembler also is available from MMS 
at a modest price.) 

Inspection of lines 10 and 11 of 
block 51 shows that assembly- 
language definitions begin with the 
word CODE (instead of [ : J ) and 
end with the word NEXT (instead 



of { ; ) ). Here, FORTH's 8080 
assembler is used to define a new type 
of word to output to a port. Both 
1CASSOUT and 2CASSOUT drive 
the cassette recorder port (I/O port 
255 on the TRS-80), and the word 
BOP executes both these words in a 
do-loop ten times to create a short 
square-wave sound on the external 
speaker. 

The definition of PCHK ("paddle 
check" of ball location) in block 53 
uses two more constructs. There are 
two if constructs, the inner one begin- 
ning in line 6 and ending in line 10, 
the outer beginning in line 5 and end- 
ing in line 11. (Notice that only the in- 
ner loop uses the optional else clause, 
as in line 9.) The second construct is a 
numeric case construct, NCASE ,■ as 
shown in line 7. When NCASE is ex- 
ecuted, it expects the number on top 
of the stack to be one of the numbers 
listed between NCASE and the dou- 
ble quote marks (here, zero thru 
seven). The value found causes the 
execution of the corresponding 
FORTH action word in the series of 
apparent numbers between the dou- 
ble quote mark and the word 
CASEND. (Numbers are words but 
are not in FORTH's dic- 
tionary — when they are "executed," 
they are pushed on top of the stack. 
MMSFORTH case statements require 
their action words to be words in the 
FORTH dictionary and not numeric 
literals, so in block 53, line 2, 2 and 
—2 are defined as constants (FORTH 
words). 1 and —1 are already defined 
as constants by standard FORTH. 
Taking { 2 CONSTANT 2 J as an 
example, the first 2 is the value of the 
constant, while the second 2 is the 
name of the constant; we might have 
used the word TWO in its place.) In 
our program, j NCASE } causes 
the word —2 to be executed. 
{ 1 NCASE } , { 2 NCASE } , 
or ( 3 NCASE j cause -1 to be 
pushed on top of the stack, and so on. 
Only one of the words is executed; 
execution then continues with the 
first word after CASEND . 
MMSFORTH also has an alpha- 
numeric case statement that branches 
on the value of a single character. 
Each may be thought of as a compact, 
structured, many-branched alter- 
native to a nested series of if 
statements. 

The Last Block 

Block 55, the last block used to 



August 1980 © BYTE Publications Inc 161 



Word Name Usage 

SPEED CVARIABLE contains speed of play. 

SPVAR CVARIABLE contains speed multiplier, depends on height ball reaches. 

SCORE VARIABLE contains current score. 

XPOS VARIABLE contains current ball X position (range, 2 thru 61). 

YPOS VARIABLE contains current ball Y position (range, 5 thru 47). 

PPOS VARIABLE contains current paddle position (range, 2 thru 54). 

XDIR VARIABLE contains current ball X increment (possible values: - 2, - 1 ,1 ,2). 

YDIR VARIABLE contains current ball Y increment (possible values: - 1,1). 

LINE Expects n on top of stack; moves cursor to line n, clears line. 

INIT Asks questions and draws display. 

PCLR Clears paddle. 

PSET Draws paddle. 

PADDLE Checks for right- or left-arrow key being pressed and moves paddle appropriately. 

1CASSOUT 8080-code procedure for sound. 

2CASSOUT 8080-code procedure for sound. 

BOP Makes one bounce noise. 

XCHK Checks if ball hit either side wall, modifies XDIR and XPOS if necessary. 

YCHK Checks if ball hit top wall and modifies YDIR and YPOS if necessary; also sets speed multiplier. 

PCHK Checks if ball at paddle level; if so, did it hit paddle or is it out of play? Leaves F on top of stack; F = if ball still in 

play, else 1 . 

CLR Clears brick, modifies score and YDIR. 

BALLCHK Increments ball position and checks for wall, paddle, or brick hits. Leaves F on top of stack; F = if ball still in play, 

else 1. 

BALL Clears old ball position, calls BALLCHK, and draws new ball; see BALLCHK for value left on top of stack. 

GAMECHK Checks if all bricks cleared and draws new barrier if so. 

DELAY Causes a given time delay between ball moves. 

BREAKFORTH Main game loop. 

Table 1: Table of variable names and FORTH words used in the BREAKFORTH program. Note that all variables leave their ad- 
dress on the stack, that LINE removes one entry from the stack before executing, and that PCHK , BALLCHK , and BALL add 
one entry to the stack after executing. 



define the word BREAKFORTH , word (which is also the program) specialized words that are helpful in 

defines one last word ( DELAY , in BREAKFORTH . This is a good solving problems of a given class or 

line 1), then puts all the words de- demonstration of how FORTH is application, then you use them to 

fined so far together to define the meant to work: first you define write the specific program needed. 



WHY CANT 
MICROPOLIS DO 

THINGS LIKE 
EVERYONE ELSE? 



162 August 1980 © BYTE Publications Inc 



(The building words, if chosen and 
defined properly, can be used to help 
write other programs in the same 
class.) 

The word BREAKFORTH is de- 
fined in lines 2 thru 14. A flowchart 
for the program is given in figure 3; 
the number to the left of each box 
gives the line number within block 55 
which the box is associated with. 

Line 15, the last line of block 55, is 
interesting in that it triggers all the 
work done so far. The word 
BREAKFORTH causes the definition 
of the word to be executed. Once the 
game is finished, the next 
words, { FORGET TASK J , are 
executed; these words cause the word 
TASK (remember block 50?) and 
every word defined after it to be 
erased from the vocabulary of the 
language. This is done to free up the 
computer once we are finished play- 
ing BREAKFORTH. You can omit 
these words if you wish, but the disk 
program is recalled into memory so 
easily (with the phrase j 50 6 
LOADS j ) that most people prefer 
to keep the FORTH dictionary as 
uncluttered as possible. The last 
word, DIR , causes the standard disk 



MMSFORTH directory to be 
displayed on the screen. (The last 
three words should be deleted if you 
are running the cassette version of 
MMSFORTH.) 

Summary 

It takes some work to understand 
your first FORTH program. But this 
work is only the flip side of the same 
coin that makes FORTH such a 
powerful language — where else can 
you easily write such a large and 
speedy program in such a small 
space? [The only other candidate 
language I can think of is APL, which 
is also known for its compactness and 
unreadability to the uninitiated. , . 
GW] But, of course, your second 
FORTH program is easier than your 
first, and so on. Better yet, your 
second program may be 90% writ- 
ten by your first, thanks to FORTH's 
structured and modular design. 

We hope you have enjoyed this in- 
troduction to FORTH. We can assure 
you that it has just scratched the sur- 
face of FORTH, which performs 
equally well in process control proj- 
ects and business applications. 
FORTH improves our programming 



skills while improving our computer's 
effective speed, memory capacity, 
and instruction set. It is a most satis- 
fying language. ■ 



Miller Microcomputer Services 
offers a number of products and 
services based on the FORTH 
language. Version 1.9 of 
MMSFORTH, the language used 
in this article, runs on a 16 K-byte 
or larger TRS-80 Model I with 
Level II BASIC. The disk version is 
$79.95, and the cassette version is 
$59.95. Each package contains the 
complete MMSFORTH system (in- 
cluding a fullscreen editor and an 
8080 assembler), FORTH source 
code, documentation, and the 
microFORTH PRIMER book from 
FORTH Inc. 

For further information, send a 
self-addressed, stamped business 
envelope to: 

MMSFORTH Information 

Miller Microcomputer Services 

61 Lake Shore Rd 

Natick MA 01760 



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But our innovations don't stop there. Over the 
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Obviously, we did 
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MICROPOLIS 

Where the 5V4-inch OEM drive grew up. 

Micropolis Corporation, 21329 Nordhoff Street, Chatsworth. CA 91311. For 
the telephone number of your nearest OEM rep, call (213) 709-3300 

August 1980 © BYTE Publications Inc 163 



FORTH Extensibility 

Or How to Write a Compiler in 25 Words or Less 



Kim Harris 

1055 Oregon Ave 

Palo Alto CA 94303 



A computer language should help users solve prob- 
lems. Languages bridge the gap between the primitive 
operations the computer can perform (add, fetch from 
memory, etc), and the tasks a user needs (invert a matrix, 
search a file, etc). When the operations of an application 
are well matched to those of a language, the solution can 
be simplified and developed in less time; in addition, the 
resulting program becomes more readable. 

Because all applications have various needs, it is im- 
possible for a nonextensible computer language to satisfy 
all needs equally well. Although languages have been 
produced which attempt to include all possible opera- 
tions, structures, and facilities, these have not been 
satisfactory. 

FORTH's approach is to provide a few techniques that 
allow a user to quickly add the special operations his par- 
ticular application requires. The remainder of this article 
will describe some of these techniques and give examples 
that add arrays (with and without subscript range check- 
ing), virtual arrays, and a case selection control 
structure. 

Extending the Language 

The ability to add language facilities and compiler 
structures is called extensibility. FORTH is extensible on 
three levels of increasing power: 

• using existing compilers 

• creating new compilers 

• creating new operating systems 



Editor's Note 

In this article, Kim Harris uses the syntax of 
FORTH-79, which is different from that of existing 
FORTH implementations, for his examples. 
FORTH-79 is a standard set of FORTH words that, if 
used to build all other FORTH words needed for a 
given application, insures the complete portability of a 
given program between different versions of FORTH. 
Members from FORTH Inc, the FORTH Interest 
Group, the European FORTH Users' Group, and 
MMS worked together to define FORTH-79. I have 
noted the differences between the text and existing 
FORTH implementations (in particular, fig-FORTH 
and MMSFORTH) where known.... GW 



This article focuses on the second level and demonstrates 
the construction and use of specialized compilers. The 
specialized compilers are usually simple (definable in a 
few source lines), but permit entire new classes of 
language or compiler facilities to be added to a FORTH 
system. 

The compilation of any computer language is dia- 
grammed in figure 1. Compilation is the process of con- 
verting a source language program into a form that a 
computer can use. 

FORTH uses multiple compilers to implement different 
compiler functions. For example, compiling a data struc- 
ture declaration (eg: an array) is distinctly different from 
compiling an executable statement. FORTH uses separate 
compilers for these two activities. Such compilers are 
many times simpler than the compilers for most popular 
languages (eg: BASIC, Pascal, COBOL); however, a 
collection of FORTH compilers can perform all the func- 
tions of the other languages' compilers (when these func- 
tions are adapted to a FORTH-like environment). 

FORTH uses the English word "word" to mean an ex- 
ecutable procedure, not a piece of memory. In this arti- 
cle, "word" will be used in the FORTH sense, and storage 
sizes will be specified in terms of 8-bit bytes. 

User-Defined Words 

The input language to the FORTH compilers is a se- 
quence of FORTH source language word-names sepa- 
rated by spaces. (Unlike other languages, a space in 
FORTH is very important.) The output is one dictionary 
definition for each new word (procedure) compiled. The 
compilation process is controlled by special FORTH pro- 
cedures called defining words. A source definition, which 
is a series of FORTH words including defining words, 
specifies a procedure that can be compiled by executing 
(typing in) the sequence. The result of compilation is a 



USER'S 
SOURCE 
PROGRAM 




EXECUTE 
COMPILER 




USER'S 
OBJECT 
PROGRAM 1 







Figure 1: Compilation of any computer language. A program in 
some computer language is input to a compiler. The compiler 
produces a functionally equivalent program in a different, ob- 
ject language. 



164 August 1980 © BYTE Publications Inc 




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BYTE August 1980 165 



(a) 



SOURCE 
DEFINITION 


, 2 * 




DUP 


+ 


'< 


DICTIONARY 
DEFINITION 


2* 


ADDRESS OF 


ADDRESS OF 
DUP 


ADDRESS OF 

+ 


ADDRESS OF 
EXIT 




NAME 
L FIELD 


CODE 
FIELD IK 


PARAMETER 

FIELD j 



BODY 



(b) 



SOURCE 
DEFINITION 



DICTIONARY 
DEFINITION 



VARIABLE % INTEREST 



ADDRESS OF 



ADDRESS OF 
EXIT 



% INTEREST 



ADDRESS OF 
VARIABLE 



SPACE FOR 
VALUE 



FROM DEFINITION 
OF 2* 



NAME 
FIELD 



CODE 
FIELD 



BODY 



Figure 2: Examples of extending the FORTH language. The first source line adds a new operator named 2 * (see figure 2a); the second 
source line adds a new operand named %INTEREST (see figure 2b). 



dictionary definition, which is a block of FORTH-inter- 
pretable instructions. All compiled FORTH words are 
kept in this dictionary, which is usually located in the 
computer's memory. 

User-defined words are treated the same as system- 
supplied words. If some new words are defined which 
behave like operators (eg: triple-precision versions of the 
FORTH words + , -,*,/, etc), then the 
language has been truly extended to include these 
operators. Subsequent words may use these new words 
as system-supplied operators. 

Examples of standard, system-supplied defining words 
are { : } (colon), which starts the compilation of subrou- 
tine-like procedures, and VARIABLE , which compiles a 
named memory location for the variable's value. 

A source definition consists of a defining word fol- 
lowed by the name of the word being defined and then by 
other FORTH words and numbers. Figure 2 illustrates the 
source definitions and the corresponding dictionary 
definitions for two new words named 2* and 
% INTEREST . (FORTH word-names may be made of 
any nonblank characters.) The word 2* simulates a 
multiplication by 2 by adding a value to itself. 

The defining word { : } compiles the words that 
follow it in a definition, which is then added to the dic- 
tionary. Each FORTH dictionary definition consists of 
two parts: a head and a body. The head contains system- 
internal information including a name field and a code 
field. (A link, which points from a definition to a 
previous definition, is part of the head but will be ignored 
in this article.) The name field contains the name of the 
word. The code field contains a pointer to the instruc- 
tions that will be executed when the word is executed. 

For definitions compiled by { : }, the code field points 
to a procedure that begins the execution of the words 
referenced in the definition. The body of this kind of 
definition, called the parameter field, is a series of ad- 
dresses that point in order to each FORTH word in the 
definition. The addresses of these referenced words are 
placed in the parameter field by the { : } compiler, and 



the definition is ended by the FORTH word { ; } 
(semicolon). The execution of the word EXIT (compiled 
at the reference to { ; }) ends the execution of the word. 

Some Examples 

The word 2* will leave a result that is twice the value of 
its input. (See figure 2a.) Examples in this article will 
underline the input typed by the user and will end in an 
unseen carriage return; the computer's response follows. 
The following line shows the use of the word 2* : 

3 2*. 6 OK 



The use of 2* causes the words in its definition to be ex- 
ecuted, as if the user had typed: 

3 DUP two copies of 3 on the stack 

+ add both 3s 

print result from top of stack 

Any subsequently compiled word may call the word 2* 
as if it were any other FORTH word. When called, 2* 
performs its function and then returns. This is analogous 
to the execution of a subroutine call in other languages. 
A word is called by simply using its name, as in the 
following source definition for 4* . 

: 4* 2* 2* ; 

The defining word { : } has been used to compile 
another definition into the dictionary. 

Using 4* will cause 2* to be called and executed twice. 
Here is an example of the use of the word 4* . 



3 4* 



12 OK 



The second word defined in figure 2 uses the defining 
word VARIABLE to compile a dictionary definition that 
contains data. The source word-name %INTEREST is 
compiled into a new dictionary definition containing a 



166 August 1980 © BYTE Publications Inc 



Level Method 

I Using standard FORTH defining words to add 
new operations (programs). 

II Creating new user-defined defining words that, in 
turn, create new classes of words. 

III Creating new FORTH-like systems through 
metaFORTH. 

Table 1: Levels of extensibility in FORTH. Level I refers to 
the act of defining ordinary words in FORTH using standard 
defining words. Level II refers to the creation of new defining 
words that are then used to create a family of ordinary 
FORTH words. Level III refers to the act of altering and re- 
compiling FORTH itself (sometimes called metaFORTH) to 
create significantly different variant FORTH-like systems. 
Higher levels imply greater capability and flexibility. 



2-byte area where the value of the variable will always be 
stored. (The use of the word-name %INTEREST , either 
inside or outside a definition, will cause the address of 
this variable's value to be returned, not the value of the 
variable.) 

The dictionary definition for % INTEREST contains 
the variable's name, a pointer to the instructions executed 
when % INTEREST is executed, and a 2-byte data area. 
The code fields of all words defined by VARIABLE point 
to a procedure which returns the address of the data area 
of the variable when the variable's name is referenced. 
All FORTH words, even data words, have some code 
that is executable. 

The two defining words of this figure are actually dif- 
ferent compilers. The defining word { : } compiles pro- 
cedure definitions, while the defining word VARIABLE 
compiles data definitions. All user-added operators and 
operands can be used exactly like the system-supplied 
ones. Even new control structures can be added to the 
FORTH compiler by the user. 

Levels of Extensibility in FORTH 

As shown in table 1, there are three levels of exten- 
sibility supported by FORTH. The two words defined in 
figure 2 are examples of extensibility level I, the most 
commonly used level. It comprises the "ordinary" act of 
programming in FORTH. Although it is very useful, this 
level is the most restrictive and the least powerful of the 
three. 

The process of writing and using new defining words is 
the second level of extensibility. Level II, which is more 
powerful than level I, allows a new "family" of words to 
be added to the language or compiler. This is done by 
creating a special word, called a defining word, that will 
be used to create FORTH words in the same family. The 
user specifies via the defining word how the compilation 
of a new family member (itself an ordinary FORTH 
word) is to be performed and what the result will be. Also 
the user specifies what a member of the family will do 
when it is executed. 

Level III, the highest level of extensibility, is called 
metaFORTH. It uses the entire FORTH system to compile 
a collection of source definitions (including both lower 
levels) in order to produce a clone or a mutation of 
FORTH. 



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YTES 
OOKS 
ARGAINS 




II 


mi 






pit 











Cromemco • SWTPC • Lear-Siegler 

Hazeltine • RCA • North Star 
Verbatim • Perkin Elmer and others 

Fast, off the shelf delivery. 
Call TOLL FREE 800/523-5355 

MARKETLINE SYSTEMS, Inc. 

2337 Philmont Ave., Huntingdon Valley, Pa. 19006 

215/947-6670 • 800/523-5355 

Dealer Inquiries Invited 



APPLE II® DISK SOFTWARE 

DATA BASE MANAGER - 

IFO PROGRAM 

The IFO (Information File Organizer) can be used for 
many applications such as sales activity, inventory, 
check registers, balance sheets, client/patient records, 
billing and much more. This can be accomplished easi- 
ly and quickly without prior programming knowledge. 

Up to 1000 records with a maximum of 20 headers 
and 1 report formats can be stored on a diskette. Infor- 
mation can be sorted and searched (3 levels). 
Mathematical functions can be performed to 
manipulate the information. Subtotals and totals can 
be calculated on any numeric field. 

Requires 48K and Applesoft II on ROM (or Apple II 
Plus). Accommodates serial/parallel printers. Error pro- 
tection devices provided. Program diskette and instruc- 
tion manual - $100. 

MAILING LIST PROGRAM - Print labels sorted or searched 
by 6 fields. On-screen editing. Line up routine. $40.00 

Inventory Program - $140 

Payroll Package - $240 (Specify state) 

Apartment Manager - $325 

Professional Time & Billing - $325 

Speed Reading - $100 

Send check/money order to: 

SOFTWARE TECHNOLOGY for 

COMPUTERS (STC) 

P.O. Box 428 

Belmont MA 02178 

or available from your local dealer 



CONTRACT 
PROGRAMMERS 

$15 to $30 per Hour 

Our clients have immediate short-and 

long-term assignments available for 

experienced programmers in either field - 

mini/mainframe. Paid weekly; 

full benefits available. 

• Software Tech. Writers 

• Software/Hardware Engineers 
(INTEL 808S) 

• Programmer/Analyst (COBOL, 
IBM, or DEC 10) 

• Systems Programmer (Mini/ 

Micro Assembly, FORTRAN, & BASIC plus) 

digital arts group 

CONTRACT 

SERVICES 

For immediate con- 
sideration, contact: 
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Nine Bedford Street 

Burlington. MA 01803 

(617)273-2780 




MicroByte Software 

241 5-C Gateway Plaza 

Crabtree Blvd. 

Raleigh, North Carolina 27604 



AT LAST! A fully implemented computer based file management system. . . 
Only a few minutes of instruction and you are creating and using your own 
client lists, mailing lists, inventories, bibliographies, vendor lists, and more. 

I) B M S 8 
Files, lists, or records, with user defined formats, can be created, sorted, 
edited, and printed with ease. Sub-files can be created oui of pans of existing 
files, selecting parts of a record or individual records by a search criterion. 
ALSO available wilh DBMS80. . . 

REPORT80 
Build your own custom defined and formatted reports and data summaries. 
Print lables with user specified formats that will fii your own forms. 
DBMS80 and REPORT80 will run under either CP/M or TRSDOS 

DBMS80 $250.00 

REPORT80 $100.00 

Manuals each $25.00 

OTHER PRODUCTS OF MICROBYTE SOFTWARE: 

KDIT80 $100.00 

Text editor and print formatter which runs under CP/M or TRSDOS 

D1SK80 $50.00 

Utility which allows you to examine and patch a disk. 

UTILS $50.00 

Apple PASCAL utilities: extensions to Apple Pascal, together with file 
control utilities, cross-reference, etc. 

PAYROL1 $100.00 

Apple PASCAL payroll for 150 employees, full 
deduction options, etc. 

Wrile or call today for further details on our products. 
Source 1D#TCE373 (gig) 833-4894 

A 1*1*1 I. is a trademark of Apple <. umpuler C orp. 
I ItSMO.s is a trademark of land* Corp. 
CP/M is a trademark of Digital Research 



168 BYTE August 1980 



Circle 113 on inquiry card. 



Circle 114 on inquiry card. 



(Please don't be misled by my use of the word "com- 
piler." I have been asked, "Can you write a compiler in 
FORTH that will compile BASIC, Pascal, COBOL...?" 
The answer is not easy. Defining words can compile 
application-oriented languages, but those languages 
should be FORTH-like in nature. Ordinarily, the 
language being compiled satisfies the syntax of 
FORTH— words separated by spaces. The compilation 
will result in FORTH-interpretable instructions that will 
add to its dictionary of word definitions. 

In keeping with the FORTH philosophy of keeping all 
definitions small, defining-word definitions are also 
small. This results in compilers (defining words) that are 
simple and specialized, although the range of complexity 
of these compilers can vary greatly. A simple defining 
word such as VARIABLE may accept only one source 
word and produce a single, simple definition in the dic- 
tionary. A more complex defining word such as { : } 
may take several source words and produces a more com- 
plex definition.) 

The remainder of this article concentrates on level II, 
defining new families of words. The scope and usefulness 
of new defining words are discussed using functional 
descriptions and examples. New defining words can be 
created which can later compile application-oriented 
languages. 

Creating Families of Words 

The technique of creating new defining words permits 



TIME: 



SEQUENCE 1 



DEFINING-WORD 

SOURCE 

DEFINITION 



EXECUTE 
EXISTING 
COMPILER 



SEQUENCE 2 



MEMBER WORD 

SOURCE 

DEFINITION 



DEFINING WORD 

DICTIONARY 

DEFINITION 



EXECUTE 

NEW 

COMPILER 



FORTH 
EVENT: 



COMPILE A 
NEW DEFINING 
WORD. 



SEQUENCE 3 



INPUT 
DATA 



MEMBER WORD EXECUTE 

DICTIONARY NEW 

DEFINITION MEMBER WORD 



EXECUTE THE 
DEFINING WORD-, 
COMPILE A NEW 
MEMBER WORD. 



OUTPUT 
DATA 



EXECUTE THE 
MEMBER WORD. 



Figure 3: The order of events governing defining words. The 
first event creates a word that will define a new family of words; 
this family currently has no members. The second event uses 
this new family-defining word to create a new family member, a 
named FORTH word. The third event occurs when any named 
FORTH word belonging to this family is used. 



The 

Working 

Analyst* 



If you would like to put 

a computer to work 
i collecting, organizing, 
' and summarizing 
the information 
you need to make 
better decisions, take 
a look at Analyst. 
Analyst is a software 
package designed to let 
you store and analyze 
virtually any information 
involving numbers, dollars, 
dates, and descriptions. Simply 
tell Analyst what kind of informa- 
tion you want to store. Analyst creates a com- 
puterized file for that information. And Analyst 
creates an information entry program for your 
file that asks you for each entry, and checks your 
data for errors. (You can create any number of 
different files.) 

Then tell Analyst what reports you want from 
your data file. There are all sorts of record 
selection and report formatting options, so you 
can design an unlimited variety of reports to 
focus on different aspects of the same data file. 

Analyst is so flexible, you'll find a million 
ways to use it. It is easy to use, so you don't need 
to be a programmer to make 
your computer really 
work for you. If this bit 
of information 
intrigues you, find out 
the rest. You'll like 
what you see. 

Analyst is a part of a full line of working software solutions from 
Structured Systems Group, all ready to run on any CP/M* microcomputer 
system. For more information, see your computer retailer, or call us. 





'CP/M is a trademark of Digital Research. 



Structured Systems 

5204 Claremont Oakland, Ca. 94618 (415) 547-1567 



Circle 115 on inquiry card. 



August 1980 © BYTE Publications Inc 169 



a user to later create a family of FORTH words that can 
have any number of members. Each member shares some 
family traits but can also have individual characteristics. 
The family members are all the words that have been 
compiled by a defining word. Their common traits are 
specified by the defining word. However, each word in 
the family has individual characteristics that are assigned 
when added to the family. 

For example, the defining word VARIABLE defines a 
family with individual members, each of which has a dif- 
ferent name and value, but all share the same execution 
trait: specifically, the use of the name of any variable 
returns the address of its value. 

It is important to understand that there are three time- 
ordered events related to defining words. These are listed 
in figure 3. These events will be explained using an 
example . 

The compilation of the new words in figure 2 is a se- 
quence 2 event (ie: using a defining word to compile 
another word). When the defining word VARIABLE is 
executed, as in: 

VARIABLE % INTEREST 

the source word % INTEREST is compiled. 

Storing a value into the variable is a sequence 3 event. 




-BEGINS 
DEFINITION 



USED AT SEQUENCE 2 



defining -word <BUILDS compile- time words 
DOES> execution - time words 



USED AT SEQUENCE 3 



-ENDS 
DEFINITION 



Figure 4: The structure of the source definition of a defining 
word. These source lines create a defining word for a new family 
(sequence 1). Execution of the defining word (sequence 2) 
<BUILDS a dictionary definition for a new family member. 
The contents of that definition is constructed by the compile- 
time words. Executing any family member (sequence 3) DOES> 
(ie: executes) the execution-time words. 



The following words store a 5 into the variable. 
5 % INTEREST ! 

Since VARIABLE is system-supplied, the sequence 1 
event (the compilation of VARIABLE ) occurred when 
the FORTH system was generated. 

< BUILDS and DOES > 

To illustrate a simple sequence 1 event, a definition of 
VARIABLE is presented. 

: VARIABLE < BUILDS 2 ALLOT DOES> ; 

The defining word { : } (colon) is used to compile the 
source definition of VARIABLE . To the word { : }, 
VARIABLE is an ordinary definition (level I), and its 
definition is a sequence 2 event for { : }. VARIABLE is a 
defining word because the special words < BUILDS and 
DOES> are used. (The < and > characters are part of 
the names of the words; they are used like parentheses to 
indicate that < BUILDS comes before DOES> .) 

As illustrated in figure 4, a defining word specifies both 
the compile-time behavior (sequence 2) and the 
execution-time behavior (sequence 3) of all words com- 
piled by this defining word. The sequence 2 behavior is 
specified by <BUIILDS and any following words up to 
DOES> . The sequence 3 behavior is specified by 
DOES> and any following words up to { ; }. The 
English meaning of < BUILDS is "compiles" and the 
meaning of DOES> is "executes." 

Figure 5 demonstrates what occurs when VARIABLE is 
executed. The end result of the execution of VARIABLE is 
that a new dictionary definition is created for the word 
% INTEREST . The following describes each step in the 
compilation of %INTEREST : 

1. The execution of VARIABLE causes < BUILDS 
to be executed. < BUILDS reads the next word- 
name after the word VARIABLE from the input 
text stream. (In this example, the next word- 
name is % INTEREST .) 

2. < BUILDS then adds the head of a new definition 
to the end of the dictionary. Within this head, 
the name field contains the member's word-name 



SOURCE FOR 




























SEQUENCE 2 


VARIABLE % 
1 


INTEREST 
/ 






1 

1 


/ 
/ 








EXECUTES WORD 


NAME 






1 / 




























DICTIONARY 




VARIABLE 




<BUILDS 




2 ALLOT 


DOES> 


EXIT 




DEFINITION / 






















1 
1 
COMPILES 
/ 
* 




1 k 
COMPILES \ 








\ \ 










n i 






RESULT OF \ 
SEQUENCE 2 ] 




% INTEREST 












NAME CODE 


\ PARAMETER 














FIE 


LD 


FIELC 


\ 


FIELD 











Figure 5: The result of executing a defining word. The first line is executed, resulting in the compilation of the word-name 
%INTEREST . The result is a new definition in the dictionary. 



170 August 1980 © BYTE Publications Inc 



Now there's a new 



that canted 
your old TRS-80 
some new tricks. 

TFOKTH. 

A unique growth programming language for the TRS-80* 

that combines the best features of an interpreter and a compiler 

all in one functional easy-to-use package. 



Introducing TFORTH from Sirius. 
A new and unique language that cannot 
be simply compared with FORTRAN or 
BASIC. TFORTH serves as an operating 
system, compiler, assembler, interpreter, 
virtual memory, file system, etc. all in 
one. Using concepts like virtual memory 
and stack organization, TFORTH makes 
easy, efficient, structures, re-entrant 
programs a natural consequence. 

TFORTH is a procedural language 
specifying a process rather than a 
desired result. The ability to have the 
language grow in the direction the user 
desires is unusual but excellent for novel 
applications. New data types and new 
processes can become part of the 
language. Due to the modular construc- 
tion, very compact code is produced 
which, even so, executes at speeds be- 
tween machine code speeds and about 
20% typical overhead. Memory re- 
quirements may be "less" than 
assembler coding or other high level 
languages. 

TFORTH provides an excellent 
way to develop new languages, or pro- 
vide simple control of devices including 
video monitors, A to D converters, 
burglar alarms and many other tasks re- 
Circle 116 on inquiry card. 



quiring monitoring and decision. Many 
words to handle peripherals are part of 
basic TFORTH and others may be add- 
ed easily. Often, substantial hardware 
development can be eliminated by using 
TFORTH to do the major digital logic 
or reduction of data. 

The key to TFORTH's flexibility 
and ease of use lies in its use of a stack 
for parameters and a dictionary for 
WORDS. These WORDS are stated in 
terms of other WORDS already defined 
in the dictionary. To execute a 
"program", the WORD is typed on the 
console and that WORD is executed. 

A rich set of WORDS comes with 
the basic language, providing IF-THEN- 
ELSE, DO LOOPS, BEGIN-END, vir- 
tual memory, any number base (to base 
32) for input or output, a macro 
assembler, re-entrant code, multithread 
dictionary, line editor, excellent math 
package (16 bit integers, Double Preci- 
sion Floating Point math [standard], 
SIN, COS, TAN, SQRT, EXP and 
LOG) and it runs under either 
TRSDOS* or NEWDOS. Assembler can 
be nested with high level in an easy 
fashion. Complicated drivers for new 
devices take only a few lines of TFORTH! 



TFORTH from Sirius comes com- 
plete for the TRS-80* with as little as 
16K of memory and a single Disk Drive 
using either TRS-DOS or NEWDOS. It 
is provided on diskettes and an optional 
Math and Utilities package is available. 

TFORTH (on diskette-specify for 
Standard or 80 Track Drives). . . $129.95 
*TM Tandy Corp. 

Among the many supported 
features of TFORTH are: 

■ A Macro-Assembler 

■ Line Editor 

■ Advanced Math Package 

■ Re-Entrant Code 

■ Faster 1/0 Operation 

■ Super Graphics Capabilities 

I High-Speed File Handling 
. . . and much more! 



JElIb) 



SIRIUS jumB 

SYSTEMS ^|pr 

7528 Oak Ridge Highway ^™ 
Knoxville, TN 3792 1 [615) 693-6583 

BYTE August I960 171 



( % INTEREST ), and the code field contains a 
pointer to the instructions that will be executed 
when % INTEREST is executed (during sequence 
3). 

3. The two words { 2 ALLOT } are executed next. 
These will reserve 2 bytes of dictionary space for 
the value of the variable. This space is in the 
parameter field of the dictionary definition. 

4. Finally, DOES> terminates the compilation of 
% INTEREST and links the code field of 
% INTEREST to the execution-time part of 
VARIABLE . 

When % INTEREST is executed (sequence 3), DOES> 
is executed, followed by the FORTH words between 
DOES> and the end of the definition. (In this example, 
there are no words following DOES > ; the word EXIT is 
a routine left by the end-of -definition word { ; }.) 
DOES> returns the memory address of the parameter 
field within the dictionary definition of % INTEREST . 
Since the parameter field of a word defined by 
VARIABLE contains only the value of that word, execu- 
tion of the word % INTEREST returns the address of its 
value, which is then pushed onto the parameter stack. 
(That is, in fact, the execution-time behavior of a FORTH 
variable.) 

Figure 6 shows an example of the execution of 
% INTEREST . 

[The above definition and usage of the word 
VARIABLE are valid for existing FORTHs. However, the 
definition of VARIABLE supplied with most FORTHs re- 



quires the initial value of the variable before the word 

VARIABLE (eg: { 5 VARIABLE %INTEREST } ). 

This definition of VARIABLE is: 

{ ■. VARIABLE <BUILDS , DOES> ; } 

...,GW] 

The previous example demonstrated the following 
principles: 

• Sequence 1: the definition of a defining word 

specifies both the compile-time behavior 
and execution-time behavior of all words 
belonging to the family of the defining 
word (ie: all words created using the defin- 
ing word). 

• Sequence 2: the execution of a defining word 

causes the compilation of the word-name(s) 
that follow. This creates a new dictionary 



(SEQUENCE 3) 



5 PUSHED ONTO THE STACK 



% INTEREST 



EXECUTES ( DOES > J 
WITHIN ( VARIABLE ) . 
THIS PUSHES THE ADDRESS 
OF THE VALUE ONTO THE STACK 

STORES THE VALUE 5 INTO 

THE ADDRESS RETURNED 

BY { % INTEREST } 



Figure 6: The execution of a family member word. The value 5 is 
stored in the variable %INTEREST . 



64K MEMORY 

FOR THE 

HEATHKIT H8' 
COMPUTER 



Assembled 

$750 
615 
480 
345 



Kit 

$650 
525 
400 
275 



64K (56K) 
48K 
32K 
16K 



Memory Expansion Kit - 16K $125 

PC Board Only - With Documentation $ 50 

Phone for Free Brochure 714/830-2092 

*HEATHKIT and H8 are Registered Trademarks of the Heath Co. 



— TRIONYX 
ELECTRONICS 

BOX 5131-C, SANTA ANA, CA 92704 



M»' 



Main/Frames ^ $2 



:v..» • 



Main/Frames $200 



• 14 Basic Models Available 

• Assembled & Tested 

• Power Supply: 
8v@15A, ± 16v@3A 

• 15 Slot Motherboard 
(connectors optional) 

• Card cage & guides 

• Fan, line cord, fuse, power 
& reset switches, EMI filter 

• 8v@30A, ± 16v@10A 
option on some models 



Rack 
mounted 
Main/Frame 



8" Floppy Main/Frame 

(includes power for 
drives and main/frames) 



Write or call for our 
brochure which includes our 

application note: 
'Building Cheap Computers' 

INTEGRAND 

8474 Ave. 296 • Visalla, CA 93277 • (209) 733-9288 
We accept BankAmericard/Visa and MasterCharge 



172 August 1980 © BYTE Publications In 



Circle 118 on inquiry card. 



Z80 Source Code 




8086 Object Code 




86-DOS® 8086 OPERATING SYSTEM ■ $ 95 

1 . Read Z80 source code file written in CP/M* 
format and convert to 86-DOS format. 

2. Translator program translates Z80 source code to 8086 source code. 

3. Resident assembler assembles the translated 8086 source code to 8086 
object code. 

4. Minor hand correction and optimization. 

(A recent 19K Z80 program translation took us about four hours to fix up. 
Even without optimization, it ran twice as fast as the original!) 



86-DOS® 

This operating system is the first complete 
package of resident software for the 8086 offered 
in the general marketplace. 86-DOS provides a 
high-level interface between the program and its 
hardware environment, with functions such as 
console I/O of characters and strings, and 
random and sequential reading and writing of 
named disk files. 

A multi-level hierarchy, made possible by the 
hardware address relocation inherent in the 8086, 
allows programs to run other programs. Complete 



error trapping of otherwise "fatal" errors (e.g. - 
disk hard errors) is possible allowing a running 
program to remain in control or to transfer control 
to a high level in the hierarchy. 

The package includes an 8086 resident as- 
sembler, a Z80 to 8086 source code translator, a 
utility to read files written in CP/M format and 
convert them to 86-DOS format, a line editor, and 
disk maintenance utilities. Price (registered SCP 
CPU owners) - $95. Others - $195. 



THE REMAINING $ 1290 BUYS OUR 8 MHZ. 16-BIT 

8086 2-CARD CPU SET TO RUN IT ON 

Also requires S-100 mainframe, 8-bit or 16-bit 
static memory (yours or ours), disk subsystem. 



b 



' CP/M is a registered trademark of Digital Research Corp. 
Circle 119 on inquiry card. 



Seattle Computer Products, Inc. 

1114 Industry Drive, Seattle, WA. 98188 
(206) 575-1830 

BYTE August 1980 173 



BUSINESS -PROFESSIONAL GAME 
SOFTWARE FOR APPLE AND TRS-80 



□ HOME FINANCE PAK I: Complete package $49.95 Apple, TRS-80 

□ BUDGET: The heart of 8 compreheniive home finance syjtem. Allows user to define up to 20 bodget 
items. Actual expense input can be by keyboard or by automatic reading of CHECKBOOK II files. Casts are 
automatically sorted and compared with budget. BUDGET produces both monthly actual /bud get/variance 
report and a year-to-date by month summary of actual costs. Color graphics display of expenses. . . $24.95 

□ CHECKBOOK II: This extensive program keeps complete records of each check/deposit, Unique check 
entry system allows user to set up common check purpose and recipient categories. Upon entry you select 
from this pre-defined menue to minimize keying in a lot of data. Unique names can also be stored for com- 
pleteness. Rapid access to check files. Check register display scrolls for ease of review. 40 column print- 
out. Up to 100 checks per month storage. Files accessible by BUDGET program $19.95 

□ SAVINGS: Allows user to keep track of deposits/withdrawals for up to 10 savings accounts. Cpmplete 
records shown via screen or 40 column printer $14.95 

□ CREDIT CARD: Keep control of your cards with this program. Organizes, stores and displays purchases, 
payments and service charges. Screen or 40 column printer display. Up to 10 separate cards $14.95 

□ THE UNIVERSAL COMPUTING MACHINE: $39.95 Apple, TRS-80 

A user programmable computing system structured around a 20 row x 20 column table. User defines row 
and column names and equations forming a unique computing machine. Table elements can be multiplied, 
divided, subtracted or added to any other element. User can define repeated functions common to a row or 
column greatly simplifying table, setup. Hundreds of unique computing machines can be defined, used, stored 
and recalled, with or without old data, for later use. Excellent for sales forecasts, engineering design analysis, 
budgets, inventory lists, income statements, production planning, project cost estimatesin short for any 
planning, analysis or reporting problem that can be salved with a table. Unique curser commands allow you 
to move to any element, change its value and immediately see the effect on other table values. Entire table 
can be printed by machine pages (user-defined 3-5 columns) on a 40 column printer. Transform your com- 
puter into a UNIVERSAL COMPUTING MACHINE. 

CICOLOR CALENDAR: HI-RES color graphics display of your personal calendar. Automatic 
multiple entry of repetitive events. Review at a glance important dates, appointments, anniversaries, birth- 
days, action dates, etc. over a 5 year period. Graphic calendar marks dates. Printer and screen display << 
summary report by month of your full text describing each day's action item or event. Ideal for anyone with 
a busy calendar. . (Apple Only) $19.95 

□ BUSINESS SOFTWARE SERIES: Entire package $199.95 Apple, TRS-80 

□ MICROACCOUNTANT: The ideal system for the small cash business. Based on classic T-accounts and 
double-entry bookkeeping, this efficient program records and produces reports on account balances, general 
ledger journals, revenue and expenses. Screen or 40 column printer reports. Handles up to 500 journal 
entries per period, up to 100 accounts. Instructions include a short primer in Financial Accounting. $49.95 

□ UNIVERSAL BUSINESS MACHINE: This program is designed to SIMPLIFY and SAVE TIME for the 
serious businessman who must periodically Analyze, Plan and Estimate. The program was created using our 
Universal Computing Machine and it is programmed to provide the following planning and forecasting tools. 

CASH FLOW ANALYSIS PR0F0RMA BALANCE SHEET SOURCE AND USE OF FUNDS 
PR0FORMA PROFIT & LOSS SALES FORECASTER JOB COST ESTIMATOR 
Price, including documentation and a copy of the base program. Universal Computing Machine $89.95 

QINVOICE: Throw away your pens. Use the ELECTRONIC INVOICE facsimile displayed on your CRT. 
The program prompts and you fill in the data, Includes 3 address fields (yours. Bill to and Ship to), Invoice 
No., Account No., Order No., Salesman, Terms, Ship Code, FOB Pt, and Date. Up to 1 items per sheet with 
these descriptions: Item No., No. of units. Unit Price, Product Code, Product Description, Total Dollar 
amount per item and invoice total dollar amount. Generates, at your option, hard copy invoices, shipping 
memos, mailing labels, audit copies and disc updates to master A/R files. (48K) $49.95 

□ BUSINESS CHECK REGISTER: Expanded version of the Checkbook II program. Handles up to 500 checks 
per month with complete record keeping. (4BK) $29.95 

□ BUSINESS BUDGET: As described above and companion program to Business Check Renister. Handles 
500 transections per month, up to 20 cost categories. Accesses BCR files for actual costs. (48K) . . .$29.95 

□ ELECTRICAL ENGINEERING SERIES: Both programs $159,95 Apple 

□ LOGIC SIMULATOR: SAVE TIME AND MONEY. Simulate your digital logic circuits before you build 
them. CMOS, TTL, or whatever, if it's digital logic, this program can handle it. The program is an inter- 
active, menu driven, full-fledged logic simulator capable of simulating the bit-time by bit-time response of a 
logic network to user-specified input patterns. It will handle up to 1000 gates, including NANOS, NORS, I re- 
verters, FLIP-FLOPS, SHIFT REGISTERS, COUNTERS and user-defined MACROS. Up to 40 user-defined, 
random or binary input patterns. Simulation results displayed on CRT or printer. Accepts network des- 
cription's from keyboard or from LOGIC DESIGNER for simulation. Specify 1000 gate version (48K re- 
quired) or 500 gate version (32K required) S89.95 

□ LOGIC DESIGNER: Interactive HI-RES Graphics program for designing digital logic systems. A menu 
driven series of keyboard commands allows you to draw directly on the screen up to 1 5 different gete types, 
including 10 gate shape patterns supplied with the program and 5 reserved for user specification. Standard 
patterns supplied are NAND, NOR, INVERTER, EX-OR, T-FLOP, JK-FLOP, D-FLOP, RS-FLOP, 4 Bit 
COUNTER and N-B1T SHIFT REGISTER. User interconnects gates just as you would normally draw using 
line graphics commands. Network descriptions for LOGIC SIMULATOR generated simultaneously with the 
CRT diagram being drawn. Drawing is done in pages of up to 20 gates. Up to 50 pages (10 per disc) can he 
drawn, saved and recalled. Specify 1090 gate (48K) or 500 gate (32K) system $89.95 

□ MATHEMATICS SERIES: Complete Package $49.95 Apple only 

□ NUMERICAL ANALYSIS: HI-RES 2-Dimensional plot of any function. Automatic scaling. At your option, 
the program will plot the function, plot the INTEGRAL, plot the DERIVATIVE, determine the ROOTS, 
find the MAXIMA and MINIMA and list the INTEGRAL VALUE. For 16K $19.95 

□ MATRIX: A general purpose, menu driven program for determining the INVERSE and DETERMINANT of 
any matrix, as well es the SOLUTION to any set of SIMULTANEOUS LINEAR EQUATIONS. Disk I/O for 
data save. Specify 55 eqn. set (4BK) or 35 eqn. (32K) $1 9.95 

□ 3-D SURFACE PLOTTER: Explore the ELEGANCE and BEAUTY of MATHEMATICS by creating HIRES 
PLOTS of 3-dimensional surfaces from any 3-variable equation. Disc save and recall routines for plots. Menu 
driven to vary surface parameters. Demos include BLACK HOLE gravitational curvature equations. .$19.95 

□ ACTION ADVENTURE GAMES SERIES: Entire series $29.95 Apple only 

□ RED BARON: Can you outfly the RED BARON? This fast action game simulates a machine-gun DOG- 
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definition and adds a new member word to 
the family of the given defining word. It 
also extends FORTH because another user- 
defined procedure is added to the language. 
• Sequence 3: the execution of a member word 
causes the execution of the execution-time 
words within the defining word that 
created the member word. 

To illustrate the versatility of defining words, examples 
of new defining words follow. These examples present 
the creation of new data structures, control structures, 
and software tools. 

Creating a String-Handling Defining Word 

To show how defining words can create data struc- 
tures, a one-dimensional array of 8-bit values will be 
created. A defining word named STRING will be con- 
structed. After STRING has been compiled, any number 
of strings may be created; each can have a different name 
and size. Before the definition for STRING is shown, an 
example will first be used to describe how STRING will 
be used. 

To create a string 5 bytes long with the name BEANS , 
the following words would be used ( BEANS is the name 
of the string, not the value put into the string): 

5 STRING BEANS 

This is a sequence 2 event that will create a dictionary 
definition for BEANS ; this definition will contain 5 
bytes of data space for the value of the string. 

To fetch or store a character in BEANS , a subscript 
will be passed to BEANS . BEANS will return the ad- 
dress of the subscripted byte. For example, the words 

3 BEANS C@ 

would fetch character number 3 from BEANS . This is a 
sequence 3 event because it is a normal use of a word 
defined by STRING . The subscript precedes BEANS 
because FORTH prefers to pass data values on a stack. 

The definition of STRING can now be written as 
shown in listing 1. This definition is similar to that of 
VARIABLE . 

The parameter for ALLOT is omitted in this definition; 
the string size declaration at sequence 2 will supply the 
size parameter for ALLOT . (The word ALLOT looks for 
the number of bytes to be reserved to already be on the 
stack; this is why the string size precedes the word 
STRING when the string variable BEANS is defined.) 

Following DOES > is the word + . This will add the 
address of the start of the string (supplied by DOES > ) 
to the subscript (supplied to BEANS at sequence 3). 
Figure 7 illustrates how this works. 



Listing Is A user-defined defining word. The word STRING , 
once defined, can be used to define new FORTH words with 
unique properties. 



( defined at ) 
( sequence 1 ) 



used at sequence 2 used at sequence 3 
STRING < BUILDS ALLOT DOES> +; 



174 August 1980 © BYTE Publications Inc 



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When STRING is executed (sequence 2), it builds a dic- 
tionary definition for BEANS , which is allotted 5 bytes 
of data space. When BEANS is executed (sequence 3), it 
does the addition of the subscript on top of the stack to 
the address of the first character within BEANS . 

The following examples show how BEANS could be 
used in a FORTH program. The word STUFF-BEANS 
will store the American Standard Code for Information 



Listing 2: Using a FORTH word created by a user-defined defin- 
ing word. The 5-character string variable BEANS was previous- 
ly defined with the FORTH statement { 5 STRING BEANS }. 
Now the word BEANS can be used like any other word in 
FORTH. In listing 2a, the five characters of BEANS are filled 
with the letters A thru E. In listing 2b, the characters are printed 
out. Listing 2c gives the results of executing the words defined in 
listings 2a and 2b. (The underline denotes user input followed 
by a carriage return; the computer output, not underlined, 
follows.) 



: STUFF-BEANS 5 



(a) 



DO 
165 



I BEANS C! 



LOOP 



:SPILL-BEANS 
(b) 


5 DO 

I BEANS C@ 
EMIT 
LOOP SPACE 


(c) 




STUFF-BEANS 
SPILL-BEANS 


OK 
ABCDE OK 



( for all of 'BEANS' ) 
( add 65 decimal to ) 
( do-loop index, yielding 
( an ASCII character ) 
( store character in the ) 
( T th byte of 'BEANS' ) 



( for all of 'BEANS' ) 

( fetch the T th character ) 

( print it ) 

( print an extra space ) 



Interchange (ASCII) characters A thru E in the string 
variable BEANS . (See listing 2a.) The word SPILL- 
BEANS will print the characters in BEANS on the user's 
terminal. (See listing 2b.) Using these words would pro- 
duce the results shown in listing 2c. 

In a similar way, multidimensional-array defining 
words may be defined; the size of each element can be 
any number of bytes. 

Since the execution-time function of all family 
members is specified only once in the definition of the 
family's defining word, programming time is reduced, 
memory space is saved, and readability is improved. By 
changing the definition of the defining word and recom- 
piling the FORTH words using it, the capabilities of every 
member word are changed. This can be done so that the 
use of all member words in a user's program is the same. 

To illustrate the power of this technique, several varia- 
tions on STRING will be presented. 

Variations on the Defining Word STRING 

The original version of STRING did not initialize the 
contents of the array when it created member arrays. The 
following version will store blanks in a string when it is 
created (at sequence 2). It is convenient to first define a 
word which allocates and blanks dictionary space. The 
definition of BLANK&ALLOT is a sequence 2 event. (See 
listing 3a.) 

Next, we create a new version of STRING that is the 
same as the original, except that BLANK&ALLOT is 
substituted for ALLOT . (See listing 3b.) (The redefini- 
tion of STRING is a sequence 1 event.) This version is 
used exactly like the original, but initialized strings are 
created automatically. 

Another variation of STRING checks if a subscript ex- 
ceeds the string size when member strings are executed 
(at sequence 3). If the subscript is less than the string size, 
the result is the same as before; but, if the subscript is 
negative or greater than the string size, an error message 



/ SOURCE FOR ] 
^SEQUENCE 2 J 



EXISTING 

DICTIONARY 

DEFINITION 



RESULT OF 
SEQUENCE 2 



5 STRING 

I 

I 

I 
EXECUTES 

I 



STRING 



BEANS 
I 
I 
I 
WORD-NAME 
I 



< BUILDS 



ALLOT 



DOES> 



EXIT 




( SEQUENCE 3 ) 



3 BEANS 



Figure 7: The creation and use of a character array. The defining word STRING is executed, causing the compilation of a dictionary 
definition for BEANS containing 5 bytes of data space. When BEANS is executed (last line), the DOES> part of the definition of 
STRING adds the address of the parameter field of BEANS to the subscript (which is 3), returning the address of the desired character 
within BEANS . 



176 August 1980 © BYTE Publications Inc 



Circle 122 on inquiry card. 



Listing 3: A more sophisticated definition of STRING . The 
word BLANK& ALLOT (shown in listing 3a) allocates space for 
and assigns blanks to a newly defined string. The new definition 
of STRING (shown in listing 3b) uses BLANK&ALLOT to blank 
out a string when it is created. 



BLANK&ALLOT 
HERE 



(a) 



: STRING 
(b) 



OVER BLANK 
ALLOT 



( get the address of the ) 

( start of the string ) 

( store blanks in the string ) 

( allocate space for the array 



< BUILDS 
DOES> + 



BLANK&ALLOT 



( used at sequence 2 ) 
( used at sequence 3 ) 



Listing 4: Another definition of STRING . This definition stores 
the size of the string variable when the variable is created and 
checks for a correct subscript when a character within the string 
variable is referenced. 



STRING 



( used at sequence 2: ) 
< BUILDS DUP , 

ALLOT 
( used at sequence 3: ) 
DOES> 2D UP 

@ U< IF 

+ 
2 + 

ELSE 

. " RANGE ERROR" 
OVER . @ . 

2 + 

THEN 



store string size in ) 
member's parameter field ) 
allocate string space ) 

duplicate both the subscript 
& parameter field address ) 
if the subscript is less ) 
than the string size ) 
add subscript to address ) 
step over the string size ) 
stored in the first 2 bytes ) 
otherwise the subscript ) 
is too large or negative ) 
print error message ) 
print string size and ) 
and bad subscript ) 
leave address of first byte, ) 
a "safe" address ) 



is produced and the illegal subscript is printed. The string 
size must be stored in the dictionary definition of member 
strings when they are compiled (at sequence 2) so that the 
range check can be made when they are executed (at se- 
quence 3). 

A new definition of STRING (a sequence 1 event) that 
does the subscript checking defined previously is given in 
listing 4. 

The range check slows the execution of every reference 
to a member string, but such checking may be useful dur- 
ing program development. Since this version and the 
original version defining STRING are used exactly the 
same, it is possible to compile this definition of STRING 
while debugging (then compile all references to it or its 
member strings). After the program has been debugged, 
the original version can be compiled (followed by the 
compilation of all references to it or its members), and the 
program will run faster. 

The next version of STRING allows very large strings 
to be created and used. 



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August 1980 © BYTE Publications Inc 177 



Virtual Strings in FORTH 

If the maximum string size exceeds the amount of pro- 
grammable memory in the computer, the only solution is 
to write your program using virtual memory manage- 
ment. This means that data stored on disk or tape is con- 
sidered part of the memory of the computer, and that all 
operations working on these data take care of reading 
and writing data between main memory and the magnetic 
storage device. 

Using virtual memory management, a program can 
operate on a string array that is larger than main 
memory; pieces of the string can be read into memory 
and written back to disk or tape when required. And, 
although this technique will slow the execution rate of a 
program using it, it may be the only way to get a problem 
solved — and better a slow solution than none at all. 

(It is more common to need to manipulate large arrays 
of numbers rather than strings. Still, the same technique 
described here can be applied to numeric or any other 
kind of array.) 

With most traditional languages, it would be necessary 
to rewrite the user program so that all array references 
would call some function that could perform the disk 
read operations. Execution time could be decreased if fre- 
quently referenced array elements were kept in memory 
as much as possible. Therefore, it would help if our 
virtual-memory-array program could keep track of what 
data is in memory as the program executes. 

To show the difficulty of implementing this technique 
in traditional languages, a FORTRAN example will be 
used. In standard FORTRAN, the statement: 



ARRAY(5,7,2)=AR1(1,2)+AR2(10,20,30) 

is equivalent to the FORTH words: 

1 2 AR1 @ 10 20 30 AR2 @ + 
5 7 2 ARRAY ! 

In either FORTRAN or FORTH, if the arrays could not 
fit into memory and were instead on disk, the array 
references would have to be changed so that some addi- 
tional procedures read and wrote selected pieces of data 
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source program would have to be changed. (In FORTH, 
the body of the program would remain the same; only the 
appropriate defining word would be changed.) 

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possible in standard FORTRAN to do the previous state- 
ment using virtual memory management of the arrays: 

TEMP = FETCH2(AR1(1,1), 1,2)+FETCH3(AR2(1,1,1), 

10,20,30) 

CALL STORE3(ARRAY(l,l,l), 5,7,2, TEMP) 

The functions FETCH2 and FETCH3 are user-written 
procedures to read the referenced array elements. The 
subroutine STORE3 is a user-written procedure to write a 
given value into an assigned array element. If a large pro- 
gram using many normal array references had to be 
changed to use FETCH and STORE calls, a lot of work 
would be required. 

FORTH's separation of control between defining 
words and their members permits the necessary changes 
to be made in the definition of the defining word; in this 



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BYTE August 1980 179 



(SEQUENCE 3 ) 



START BLOCK # 



subscript BEANS 




Figure 8: Accessing a virtual array. The data for a large array is 
kept on a disk. When a byte is referenced, BEANS is executed. 
One block containing the byte is read into a memory buffer (if it 
is not already present). Finally, the memory address of the 
referenced byte is returned by BEANS . 




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way, the program that uses the arrays does not have to be 
changed. 

Furthermore, FORTH's virtual memory facility for 
disk reading and writing automatically keeps track of 
what data has been read into memory and tries to keep 
frequently referenced sections in memory. 

Figure 8 illustrates how the array will be read in blocks 
of 1024 bytes into memory buffers. The new definition 
for the defining word STRING is given in listing 5. 

Adding New Control Structures 
with Defining Words 

The next example illustrates the use of defining words 

to add control structures to the FORTH compiler. 

FORTH supplies { IF ... ELSE ... THEN } compiler 

structures and also loop structures like { DO ... 

LOOP },{ BEGIN ... UNTIL }, and { BEGIN 

... WHILE ... REPEAT } loops. 

In this example, we will create a case (choose one of n 
alternatives) selection mechanism. A case number will 
designate one of several words to be executed. Figure 9 
presents how a case statement selects one of several pro- 
cedures for execution. No matter which one is chosen, ex- 
ecution continues with one common procedure that 
follows the case structure. 

The new defining word will be named { CASE: } 
and can be used similarly to { : }, as the following 

Listing 5: Another definition of STRING . This definition 
creates a virtual string array that stores the string on disk and 
reads it into main memory when necessary. With this definition 
of STRING , it is possible to manipulate a string that is larger 
than main memory without changing the program that uses the 
long string. The disk operations are transparent — that is, the 
programmer does not know he is using the disk except for 
response time. 



STRING 



( used at sequence 2 ) 

< BUILDS NEXT-BLOCK/? 



DISK-ALLOT 

( used at sequence 3 ) 
DOES> @ 

SWAP 

1024 /MOD 



ROT + 
BLOCK 



qet the next available ) 
disk block § ) 

store it in the member's ) 
parameter field ) 
reserve disk space for ) 
the array ) 

get start-block § ) 
subscript on top, ) 
start -block § beneath ) 
divide subscript by ) 
# bytes in a disk block; ) 
the quotient is the block ) 
index within the array; ) 
the remainder is the byte ) 
index within the block ) 
add start -block § to the ) 
block index ) 
call the FORTH virtual ) 
disk manager to read the ) 
referenced block; ) 
if it is already in memory ) 
no read is performed ) 
add the byte index to the ) 
memory address of the ) 
buffer where the block is ) 
located, the result is ) 
a memory address of the ) 
byte specified by the ) 
subscript before BEANS ) 



180 August 1980 © BYTE Publications Inc 



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Circle 127 on inquiry card. 



BYTE August 1980 



181 



example shows. (In this implementation of the case con- 
struct, the selection of a case causes the execution of one 
FORTH word. Since there is no restriction as to the inter- 
nal complexity of a given word, the selection of one case 



Listing 6: Example of a new user-defined programming con- 
struct. In listing 6a, we define the words we want to execute 
when the numbers 0, 1, and 2 are on top of the parameter stack. 
In listing 6b, the user-defined defining word 
{ CASE: } defines the word ANIMAL , which will execute 
OPET , 1PET , or 2PET , depending on the value on top of the 
parameter stack. Listing 6c illustrates what happens when the 
case-word ANIMAL is executed. See listing 7 for the definition 
of { CASE: } . 



OPET 
1PET 
2PET 
(a) 



" AARDVARK 
BEAVER " ; 
COUGAR " ; 



( print the quoted string ) 
( when executed ) 



( sequence 2 ) 

(b) 

( sequence 3 ) 
(C) 



CASE: ANIMAL OPET 1PET 2PET 



ANIMAL 

1 ANIMAL 

2 ANIMAL 



AARDVARK OK 
BEAVER OK 
COUGAR OK 



Listing 7: Definition of the defining word { CASE: } in 
FORTH-79. This word allows the user to create case-words that 
execute one of several FORTH words depending on the value on 
top of the parameter stack. 



CASE: 



used at sequence 2 
< BUILDS 

] 
used at sequence 3 
DOES> 
SWAP 2* 



EXECUTE 



create head for member ) 
begin ':' compilation ) 



( convert case number to ) 

( a byte index ) 

( fetch the address of the ) 

( indexed case word ) 

( execute the selected word ) 



can cause any combination of conditional, loop, or case 
structures to be executed.) 

In our example, let us first define three words, 
OPET , 1PET , and 2PET , that are to be executed 
when the value on top of the stack is 0, 1, or 2, respec- 
tively. This is done in listing 6a. Then we use the 
{ CASE: } defining word (which we will look at later) to 
define the word ANIMAL (listing 6b). Now that 
ANIMAL and the case words it uses are defined, calling 
ANIMAL with the appropriate value on the stack ex- 
ecutes the proper case word (listing 6c). For example, 
pushing a 2 onto the stack and calling ANIMAL causes 
word 2PET to be executed; this causes the English word 
COUGAR to be printed. 

Since { CASE: } is a defining word, ANIMAL is a 
member of the { CASE: } family. The definition of 
ANIMAL consists of a list of addresses for the case words 
associated with ANIMAL. 

The definition of { CASE: } is a sequence 1 event. 
Listing 7 shows the definition of { CASE: } in 
FORTH-79. [Listings 8a and 8b show the same definition 
forfig-FORTH and MMSFORTH, respectively.... GW] 
Figure 10 shows how the word ANIMAL is built using 
{ CASE: }. The { : } compiler is used to compile the 
words following ANIMAL. When ANIMAL is 



CASE NUMBER 



OCASE 




2CASE 



Figure 9: The function of a case control structure. The case 
number selects one of several procedures for execution, then 
continues along a single exit path. 



SOURCE FOR 
SEQUENCE 2 



EXISTING 

DICTIONARY 

DEFINITION 



RESULT OF 
SEQUENCE 2 



OPET 1PET 2PET 




PARAMETER 
FIELD 



Figure 10: The creation of a case control word. The execution of { CASE: } causes a definition for ANIMAL to be appended to the 
dictionary. The ']' word uses the { : } compiler to compile the addresses of the case words following ANIMAL . 



182 August 1980 © BYTE Publications Inc 



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BYTE August 1980 183 



Listing 8: Definition of the defining word { CASE: } in fig- 
FORTH (listing 8a) and in MMSFORTH (listing 8b). 

( CASE: as implemented in fig-FORTH) 
: CASE: < BUILDS SMUDGE ] 

D O E S > SWAP 2* 
(a) + @ 

EXECUTE 



( CASE: as implemented in MMSFORTH) 



) 



( new word )) replaces SMUDGE 
: )) 1 STATE C! 21144 ; 
: CASE < BUILDS )) 

DOES> SWAP 2* 

(b) + @ 2 + 

EXECUTE 



Listing 9: Definition of a defining word that acts as a program- 
ming tool. The word LOADED-BY allows the user to execute 
(or load) a screen by name rather than by number. For example, 
if you define { 125 LOADED-BY ACCOUNTING }, ex- 
ecuting the word ACCOUNTING will have the same effect as 
executing the phrase { 125 LOAD }. 



( sequence 1 



LOADED-BY < BUILDS , 

DOES> (E 
LOAD 



( store screen # ) 
( in members def. ) 
( fetch screen # ) 
( load it ) 



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executed, the case number that precedes it (which is tvovj 
on top of the stack) is used just like an array subscript to 
calculate the address of the case word to be executed. Its 
compiled address is then fetched and executed. 

As with array-defining words, many variations of 

{ CASE: } can be constructed. A case number-range 

check may be added. An "otherwise" case word can be 

specified to be executed whenever the case number is out 

of range. 

Defining Words as Programming Tools 

The final example applies defining words to the crea- 
tion of software tools. Such tools are conveniences for 
the user. Good tools can increase a programmer's pro- 
ductivity, reduce errors, and improve program read- 
ability. Defining words can be used to add powerful tools 
to the FORTH language and operating system. 

In FORTH, the word LOAD will compile source defini- 
tions from the disk starting at a specified screen number. 
A screen is a block of disk space where source text can be 
stored using an editor. Additional screens may be loaded 
if the initial screen contains more LOAD commands. 

Application programs and utility programs begin on 
various screen numbers determined by the user. The 
defining word LOADED-BY allows words to be defined 
which will LOAD a screen without calling it by number. 

For example, assume a business application starts on 
screen 125. Then the defining word LOADED-BY can be 
used to define a word that will load screen 125 when the 
member word is executed. When we define: 

125 LOADED-BY ACCOUNTING 

screen 125 will be loaded when the single word AC- 
COUNTING is executed. (If LOADED-BY looks strange, 
think of it as a FORTH word like VARIABLE .) 

The definition of LOADED-BY is given in listing 9. 
This definition is similar to the definition of the word 
CONSTANT except that, rather than returning the value 
stored in the definition of the member word, LOADED- 
BY uses that value to provide a parameter to the word 
LOAD . 

Summary 

FORTH exploits its own extensibility to support a 
user's need for a variety of language facilities and com- 
piler structures. 

A defining word controls the compilation and execu- 
tion of all words compiled by it. New defining words that 
define a new family of capabilities may be constructed. 
Subsequently, any number of individual members can be 
added to the family. 

The source definitions of most defining words are short 
and simple. Proper use of defining words in a software 
development project reduces program development time, 
improves program readability, and makes program mod- 
ification and maintenance easier. 

Defining words are applicable to data structures, con- 
trol structures used by the FORTH compiler, and soft- 
ware tools. The ability to create new kinds of defining 
words (which are, in their own way, small compilers) is a 
unique feature of FORTH and is one of the most powerful 
programming tools in the language. ■ 



184 August 1980 © BYTE Publications Inc 



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BYTE August 1980 185 



Gregg Williams 
Editor 



This glossary is a compilation of most of the FORTH 
words used in the listings and figures of all the FORTH 
articles in this issue. It does not include all the standard 
words in FORTH (there are quite a few), nor does it 
include user-defined words required by each article. The 
pronunciations of some words are given in parentheses. 
Wherever possible, an example is given showing the use 
of the defined word. The words "before" and "after" 
show the stack before and after the word is executed. In 
these representations of the stack, the top of the stack is 
the rightmost number, and the words influenced by the 
defined word are depicted in boldface. 

The columns marked "uses" and "leaves" show how 
the execution of a FORTH word affects the top entries of 
the stack. FORTH words remove the stack entries they 
use and sometimes leave one or more entries on the stack. 
Therefore, the number under "uses" and "leaves" should 



equal the number of entries in boldface in the "before" 
and "after" stacks. Asterisks in both columns mean that 
the numbers are not given for multiword constructs for 
the purpose of clarity. 

Multiword constructs, like the following example: 



{ IF 



ELSE 



THEN } 



are enclosed in braces with the keywords separated by 
ellipses that represent zero or more FORTH words. Also, 
these constructs are listed only under the first word of the 
construct. In general, all the words in this table are sorted 
by ascending ASCII value — for example, the word * 
(ASCII hexadecimal 2A) is listed before the word + 
(ASCII hexadecimal 2B). 

This glossary assumes that the output device used by 
the FORTH system is a video terminal. When any defini- 
tion refers to the video display or display, it actually 
refers to whatever output device or devices are currently 
enabled. 



FORTH Glossary 



Word 

{ ! } (store) 



{ " } 

{ ' } (tic) 

{ ( } 



+ 



{ , } 



{ • } 



Uses Leaves Notes 

2 Sees top-of-stack as address of a 2-byte variable and stores second-on-stack in this 

variable; for example, suppose that address 20000 points to a 2-byte variable; 
then: 

before: 9 9 -1150 20000 

after: 9 9 ( — 1150 is stored in a 1-byte variable.) 

{ " HI THERE!" }, when executed, prints HI THERE! on the video display. 

1 Puts onto top-of-stack the address of the word that follows it. 

{ ( THIS IS A COMMENT) } , if included in a definition, will not be compiled; 

{ ( } requires a { ) } to end the comment. 

2 1 Multiplication; example: 

before: 9 9 3 5 
after: 9 9 15 
The word * multiplies 5 and 3, leaving 15. 

2 1 Addition; example: 

before: 9 9 3 5 
after: 9 9 8 
The word + adds 5 and 3, leaving 8. 

1 Embeds the number on the top of the stack into a dictionary definition, increment- 

ing the dictionary pointer. 

2 1 Subtraction; example: 

before: 9 9 3 5 
after: 9 9-2 
The word — subtracts 5 from 3, leaving —2. 

1 Displays the number on the top of the stack; example: 

before: 9 9 3 5 
after: 9 9 3 (5 is printed on screen.) 



186 August 1980 © BYTE Publications Inc 



YOU KNOW WATSON, (l 
HAXDEN SOFTWARE \ 
OFFERS THE BEST 
SEASONS TO OWN A 
MICROCOMPUTER... 



I had heard everyone speak about 
Hayden software. How it was the finest available. 
"I would be so pleased," said I, "if we could discuss 
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"Sounds delightful, Watson. This 
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has 7 levels of play, and levels 0-3 play in tour- 
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but 0. Imagine that, old fellow. Small wonder 
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(#03403, TRS-80 Level II; #03404, Apple II; 
each $29.95; #03409, Apple II Disk Version; 
#03408, TRS-80 Disk Version; each $34.95) 

I then looked around, and spotted 
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MANAGER looks to be as fine a specimen as 
that SARGON II . It stores up to 96,000 alphanu- 
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on just eleven diskettes one can store and retrieve 
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C #04909, Apple II Disk, $49.95) 

"Extraordinary. Here's another pro- 
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gram in any increment, and much more. I wonder 
what other fine programs are to be had from 
Hayden?" (#03504, Apple II, $29.95) 

Holmes leaned back, still puffing at 
his black pipe. "Wait a minute," said he. "Here's 
something." 



Apple is a trademark of Apple Computer Company, Inc. 
and is not affiliated with Hayden Book Company, Inc. 

Circle 130 on inquiry card. 




"What is it?" said I. 

"It's APPLE ASSEMBLY LANGUAGE 
DEVELOPMENT SYSTEM. It features a cursor- 
based editor, global and local labels, and disk-based 
macros which allow you to incorporate subroutines 
into any program. And, one can write and modify 
machine language programs quickly and easily. 
It is indeed quite remarkable." 
(#04609, Apple II Disk Version, $39.95) 

"Quite. But let us not forget BLACKJACK 
MASTER, what. Unlike other blackjack pro- 
grams that emphasize graphics and harmless fun, 
this is a serious game. Imagine being able to per- 
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playing and betting strategies that are entered 
into the microcomputer. And, it will tutor one in 
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there's also a $250.00 BLACKJACK Challenge! 
(#05303, TRS-80 Level II, $19.95; #05308, 
TRS-80 Disk Version, $24.95) 

"What is that ?" 

"My dear fellow, just see the package 
for details! Holmes, you do agree then, that these 
programs are a fine lot?" 

"I'm satisfied, Watson." 

"A very sensible reply, Holmes. It's 
simple to see why one would want to own a micro- 
computer when Hayden software is available. 
It's easy-to-use, ready-to-run, comes with full 
documentation, and can be had at any local com- 
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postage and handling." 

~||~ "I "Splendid. Holmes, simply splendid." 

Hayden Book Company, Inc. 

50 Essex Street, Rochelle Park, MJ 07662 
*From Missouri, call ( 1-800-892-7655, ext. 302) 

BYTE August 1980 187 



Division; example: 

before: 9 9 13 2 

after: 9 9 6 
The word / divides 13 by 2, leaving 6. (Remainder is lost.) 



0< 



If top-of -stack is <0, it is replaced with a 1 (true); if top-of-stack is > 0, it is 
replaced with a (false); example: 

before: 9 9 3 5 

after: 9 9 3 



1 + 



Adds 1 to top-of-stack; example: 
before: 9 9 3 5 
after: 9 9 3 6 



{ : 



{ : } begins the definition of a word; { 
{ : 3* 3 * ; } 
defines the word 3*. 



} ends the definition; example: 



If the two top items on the stack are exactly equal, both of them are removed and 
replaced with a single 1 (true); if not, both are replaced with a single (false); 
example: 

before: 9 9 3 5 

after: 9 9 

If the second item on the stack is less than the top item on the stack, both of them 
are removed and replaced with a single 1 (true); if not, both of them are replaced 
with a single (false); example: 

before: 9 9 3 5 

after: 9 9 1 



TARGET HOST -TARGET HOST 

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CROSS COMPILE AN ENTIRE FORTH SYSTEM WITH 
ALL FORWARD REFERENCES RESOLVED IN A SINGLE 
PASS TO PRODUCE AN EXCUTABLE IMAGE IN MEM- 
ORY OR ON DISK AND A LOAD MAP OF ALL DEFINED 
SYMBOLS. THE CROSS COMPILER IS WRITTEN IN 
HIGH LEVEL FORTH INTEREST GROUP (FIG) FORTH. 
A COMPLETE DESCRIPTION OF EACH WORD IN THE 
CROSS COMPILER IS GIVEN WITH STEP BY STEP 
STACK CONTENTS. FORTH INTERNALS (NEXT, BUILD, 
DOES, CREATE, ETC.) ARE ALSO COMPLETLY DE- 
SCRIBED. A CROSS COMPILABLE VERSION OF THE 
FIG MODEL 1.0 IS PROVIDED FOR THE 8080 WITH AN 
ASSEMBLER / DISASSEMBLER. THIS MAY BE EASILY 
CONVERTED TO ANY MACHINE. A DETAILED DE- 
SCRIPTION IS GIVEN FOR FIRST TIME IMPLEMENTA- 
TIONS. THE ENTIRE PACKAGE IS AVAILABLE FOR $70. 
FROM: 

Nautilis Systems 

P.O. Box 1098 

Santa Cruz, CA. 95061 

FOR THE SERIOUS FORTH USER 



CO 

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© 

cc 

< 

H 
A 

H 

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TARGET HOST —TARGET HOST —TARGET HOST 



ANNOUNCING: 



NEW! 



MICROSTAT 

A complete statistics package for business, scientific, 
education and research work. No other package has 
the features of MICROSTAT. For example: 

1 File oriented with COMPLETE editing 
A Data Management Subsystem for editing, sort- 
ing, ranking, lagging, data file transfers PLUS 1 1 data 
transformations (e.g., linear, reciprocal, exponential, 
etc.) • Frequency distributions • Simple and multiple 
regression • Time series (including exponential smooth- 
ing) »11 Non-parametric tests • Crosstabs/Chi-square 

• Factorials (up to 1,000,000!), permutations, combinations 

• 8 Probability distributions * Scatterplots 

• Hypothesis test (Mean, proportion) • AN0VA 
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Users manual: $10.00 (credited towards purchase) 
and includes sample data and printouts. Uses 
NORTH STAR BASIC 32K of memory, one or two disk 
drives (2 recommended). Printer optional. Price: $200.00 

n ECOSOFT Ph . 

A Phone orders: 

P.O. Box 68602 



Indianapolis, IN 46268 



(317)253-6828 



188 August 1980 © BYTE Publications Inc 



Circle 131 on inquiry card. 



Circle 132 on inquiry card. 



Stack Work's 



JWJM 



A full, extended FORTH interpreter/compiler produces 
COMPACT, ROMABLE code. As fast as compiled FORTRAN, 
as easy to use as interactive BASIC. 

SELF COMPILING 

Includes every line of source code necessary to recompile 
itself. 




EXTENSIBLE 

Add functions at will. 



CP/M* COMPATIBLE 



Z80 & 8080 ASSEMBLERS included 

Single license \ 

Supplied with extensive user manual and tutorial: \\ 

$150.00 

Documentation alone: $25.00 

OEM's, we have a deal for you! 

CP/M Formats: 8" soft sectored, 5" 
Northstar, 5" Micropolis Mod II. 

Please specify CPU type 
Z80 or 8080 



All Orders and General Information: 

SUPERSOFT ASSOCIATES 

P.O. BOX 1628 

CHAMPAIGN, IL 61820 

(217)359-2112 

Technical Hot Line: (217) 359-2691 

(answered only when technician is available) 





VISA 




SuperSoft 

First in Software Technology 



*CP/M registered trademark Digital Research 




Circle 133 on inquiry card. 



BYTE August 1980 189 



{ < BUILDS 
... DOES> } 



{ 1 } 
@ (fetch) 

ALLOT 
AND 

BASE 



* Used to define new defining words; see "FORTH Extensibility" article, figure 4. 

1 Similar to entry for < ; example: 
before: 9 9 3 5 
after: 9 9 (3 is not less than 5.) 

Sees top-of-stack as address for 2-byte variable; displays value of that variable; 
using the example for { ! } , then: 

before: 9 9 20000 

after: 9 9 ( — 1150, contents of 20000, prints on screen.) 

1 Sees top-of-stack as address for 2-byte variable and replaces it with value of that 
variable; using the example in { ! } : 

before: 9 9 20000 

after: 9 9 -1150 (-1150 is contents of 2-byte variable at 20000.) 

Sees top-of-stack as number of bytes to be reserved (and filled in later) during the 
definition of a word. 

1 Does an AND operation on the corresponding bits of the top two stack entries 
(both 16-bit numbers); example: 

before: 9 9 3 5 

after: 9 9 1 (3 AND 5, in binary, is 1.) 

1 BASE is a 1-byte variable that contains the number base being used; for example, 
{ 2 BASE C! } causes all subsequent input and output to be in binary (base 2); 
execution of this word causes the address of this 1-byte variable to be placed on 
top-of-stack. 



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190 August 1980 © BYTE Publications Inc 



Circle 134 on inquiry card. 



Circle 135 on inquiry card. 



JOIN THE APPLE INFANTRY ! 



Judging by the letters we've received 
from buyers of Computer Bismarck,™ 
home computer historical wargaming 
is a great mind-stretching recreation 
to uncramp the old synapses after a 
few hours of trying to cram 54K of 
code into 48K of memory. But 
before you read any further, let us 
warn you that our neui game, 
Computer Ambush,™ is more gut- 
wrenching than mind-stretching. 

Strategy versus Tactics 

Computer Bismarck is a "strate- ' 

gic" wargame, casting you in the role 

of a British or German admiral coolly 

deploying fleets of ships and planes. 

Computer Ambush is "tactical". ..tough 

and dirty street fighting in a half-ruined 

French town. 

You re a Sergeant 

You command a squad of ten infantrymen 

(either American or German). Each man has a 

name, rank, and such individual combat skills as footspeed, 

strength, intelligence, endurance and marksmanship. ..all of 

which affect the success of every move you order. Your 

squad is armed with grenades, rifles, automatic weapons, 

plastic explosives, bayonets, and even garottes. You fight 

with carefully-aimed shots, area bursts, explosions, and 

hand-to-hand combat. They can result in wounds or 

deaths, depending on time, distance, the individual skills of 

each soldier, and your ability as a squad leader. 

Battlefield 

Street fighting is the most challenging tactical command 
situation in modern warfare. Using "Higher Text", a 
character generator, the computer displays a map showing 
buildings (your plastic explosives can turn them into rubble 
during the game) , walls, hedges, doors, 
windows (nasty sniper positions), and 
each of your men by name. The 
enemy is usually hidden. 

Play the Computer 

The computer plays the Ger- 
man squad leader (Feldwebel Kurt 
Reich) to perfection. It defends the 
town with sniping, machine guns, 
grenades, and finally, with hand-to- 
hand combat. 

You're Sergeant Buck Padooka. 
You maneuver your men and fire at 
revealed and probable German posi- 
tions. If you kill all the Germans 
before they get you, the town is yours. 
But the computer's a tough, experi- 
enced squad leader, so don't expect 
to win very often. 

Play a Friend 

You take turns examining the 





video map display, moving your men, 
and firing weapons. Your options are 
imited by casualties, wounds, physi- 
cal exhaustion, ammo supplies, ter- 
rain, and the individual skills of 
each of your men. The same is 
true for your opponent. And every 
action takes precious time, even 
the flight of a grenade or bullet. 
(Remember, time is life or death 
on the battlefield and in Computer 
Ambush!) After each turn, the 
computer displays the movements 
and weapons fire of both squads as 
tracks on the video map.. .just once, 
so watch carefully to figure out where 
the enemy is, or was. 

The Sweat and Death of War 

The time pressure and complexity 
of Computer Ambush create the stress of 
actual combat command. Your palms sweat 
as you watch PFC Chuck Lawson get blown 
away by that damned Kraut machine gun you forgot when 
you ordered him to sneak across the alley. If you can 
imagine a game that's more complex than chess, requires 
much faster decision-making, rewards courage and cruelly 
punishes foolhardiness... that's Computer Ambush! 

$59.95 and an Apple 

If you've got an Apple II Plus (or an Apple III or an 
Apple II with Applesoft Firmware ROM Card) with 48K 
memory and a 5 l A inch mini-floppy disc drive, you can be 
playing Computer Ambush in a few days. For $59.95, you 
get the game program disc; 2 mapboard charts (for plotting 
strategies in grease pencil while your opponent is at the 
computer); 2 squad leader's data cards; and a rule book. 
You also get a game selection card which tells you how to set 
up any of seven wargames: NCO 
Training, Ambush or Raid against the 
computer; and Patrol, Ambush, 
Strongpoint, or Free Form against a 
human opponent. 

Call 800-648-5600 (toll free), 

and ask Operator 181 to charge Com- 
puter Ambush (or Computer Bis- 
marck) to your VISA or MASTER- 
CHARGE. In Nevada call 800-992- 
5710. To order by mail, send your 
check to Strategic Simulations Inc., 
Dept. B, 450 San Antonio Road, 
Suite 62, Palo Alto, CA 94306. 

With our 14-day money back 
guarantee, your satisfaction is assured. 
So come and join our Apple Infantry! 




COMPUTER AMBUSH™.. You Ve got a war on your hands. 



Circle 136 on inquiry card. 



BYTE August 1980 191 



{ BEGIN 
... UNTIL } 



Looping construct that tests at the end of the loop; see "What Is FORTH?" article, 
figure 4. 



{ BEGIN 
... WHILE 
... REPEAT } 



Looping construct that tests at the beginning of the loop; see "What is FORTH?" 
article, figure 5; other forms are { BEGIN ... PERFORM ... PEND } and 
{ BEGIN ... IF ... WHILE }. 



{ C; } 
{ C! } 



Sometimes used to end a machine-code word definition; most versions use NEXT. 

Similar to { ! } except that only low byte of second-to-top is stored in 1-byte 
variable pointed to by top-of-stack; for example, suppose that address 21000 
points to a 1-byte variable; then: 

before: 9 9 103 21000 

after: 9 9 (103 is stored in 1-byte variable.) 

Note that the maximum value that can be stored in 1 byte is 127. 



C@ 



Same as the word @, only for 1-byte variable; using the example of { C! } 
then: 

before: 9 9 21000 

after.- 9 9 103 (103 is contents of 1-byte variable at 21000.) 



{ CODE 
NEXT } 



Defining words, used like { : } and { ; } , used when defining a new 
word using assembly language only. 



CONSTANT 



Creates a constant that has the value of top-of-stack; for example, before ex- 
ecuting the phrase { CONSTANT CON } , the stack looks like: 
9 9 25140 




MICRO MISCELLANY 



$79.95 



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keyboards, and JBE A-D D-A Converter 
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Redwood City, CA 94064 

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less than $20. Add 4% for VISA or M.C. 



JOHN BELL ENGINEERING 



FULL COLOR 

GRAPHICS 

The original 256- color imaging system with 
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Capture and digitize a video frame in 1 /60 of a 
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• Choice of 1, 2, 4, 8, 1 6 or 32 bits per pixel 

• 32K-byte Image memory on the basic system 

• 32, 64, 128 & 256K byte system capacity 

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415/494-6088 



192 August 1980 © BYTE Publications Inc 



Circle 137 on inquiry card. 



Circle 138 on inquiry card. 



Put your applications 

to work on the Mostek 

STD-Z80 BUS. 




You're 
ready. You've 
gone beyond the 
learning stage and are using your 
personal computer to implement 
real time control applications. 

We can take you one big 
step further. By showing you how 
to take the programs you have 
developed using your TRS-80 
(or other Z80 based computer) 
and place them in PROM on a 
low-cost stand-alone micro card 
system. This will not only free up 
your main computer for new ap- 
plications, but will also permit 
your current application to be 
"on-line" continuously, or even 
"cloned"- for multiple installations 
or sales to other users. 

Mostek's MD Series of STD- 
Z80BUS compatible microcomput- 



er cards makes all this possible. 
There are more than twenty dif- 
ferent boards in this off-the- shelf 
family available now, including 
data processing boards; memory 
boards (Static and Dynamic RAM, 
ROM/PROM); I/O cards; A/D; D/A; 
high speed floating point math; 
and floppy disk controller cards. 
QC Micro Systems offers all 



support software and, 
of course, extensive 
documentation. And much more. 
Contact us for details so they can 
be put to work for you, by 
sending in the coupon below. 
Today. QC MicroSystems, P. 0. 
Box 401326, 
Garland, TX 
75040, (214) 
343-1282. 




of these 

Yes! I'm ready for more information on the STD-Z80 BUS products from 
QC MicroSystems. My application is 

□ Personal □ Resale 

□ Industrial Control D Other 



products 
directly, 
including 
a full range 
of support 
products 
such as 
prototyping 
hardware, 



□ Yes, I would like to use my TRS-80 as my STD BUS development station. 



Company - 



City 



. State 



Zip 



Circle 139 on inquiry card. 



BYTE August 1980 193 



Circle 140 on inquiry card. 



COLOR SOFTWARE 

Unless otherwise noted all programs are $15 each, for Apple II, 

Atari 1 6K, Tl 99/4 

UNITS: Practice converting yards-feet- 3-D STARTREK: Discover new planets, fight ROADRACE: Race around 2.25 mile course, 
inches, pounds-ounces, metric units, etc. Klingons in 3-dimensional galaxy. 1 or 2 players. Not for Tl 99/4. 

FRACTIONS: Practice adding, subtracting, MAJOR LEAGUE BASEBALL: Manage Major BLACKJACK: Popular card game to Uo 3 

multiplying and comparing fractions. League teams and make all lineup, batting, players. Not for Apple II. 

....... -... nr .»-r nn r, i- ■ pitching and running decisions. $25. Apple II 

NUCLEAR REACTOR: Realistic dynamic ^ 4 y 8K ft lesof u t RQM and one ^ 

model of nuclear power plant in operation. 

COLOR SOFTWARE, 5410 W. 20th St., Indianapolis, IN 46224 



After the phrase has been executed, the stack looks like: 

9 9 
and the word CON , when executed, will place 25140 on the top of the stack. 

CR Causes the cursor to jump to the beginning of the next line of the display. 

{ DO ... 2 Looping construct that specifies a beginning and an ending-value-plus-one; see 

LOOP } "What Is FORTH?" article, figure 3. 

DROP 1 Drops top entry from stack; example: 

before: 9 9 3 5 
after: 9 9 3 



DUP 



Duplicates item on top-of -stack; example: 
before: 9 9 3 5 
after: 9 9 3 5 5 



ECHO 



Isolates the low-order byte of the 2-byte entry on top of the stack and writes it to 
the video display; example: 

before: 9 9 32 

after: 9 9 (A space, ASCII decimal 32, is printed.) 

ECHO is named EMIT in some versions. 



FILL 



Fills an area of memory with a given value; for example, 

{ 255 3000 100 FILL } fills memory locations from 3000 thru 3099 (100 bytes) 
with the value 255. 



FORGET Causes system to delete all definitions including and after the word following 

FORGET ; for example, { FORGET BASEPGM } causes the system to delete 
BASEPGM and all FORTH words, variables, and constants defined after it. 




S-100 8086 

CPU with $450. 

Vectored Interrupts 

PROM-I/O $495. 

RAM $395. 

8K x 16/16K x 8 

Parallel I/O $350. 

and Timer 



| IN STOCK | 

A/D - D/A 

S-100 A/D 

8 Ch. Differential or 
16 Ch. Single-Ended, 
12 Bit, High Speed $495. 

S-100 D/A 4 Channel 
12 Bit, High Speed $395. 

TRS-80 A/D-D/A 

12-Bit, High Speed 
Available Soon 




S-100 VIDEO 
DIGITIZATION 

Real Time Video $850. 
Digitizer and Display 
Computer Portrait 
System $4950. 



S-100 Boards 

Video and/or Analog 
Data Acquisition 
Microcomputer Systems 



EC RR 



XNC. * 

The High Performance S-100 People 

TECMAR, INC. 

23414 Greenlawn • Cleveland, OH 44122 
(216) 382-7599 



194 August 1980 © BYTE Publications In 



Circle 141 on inquiry card. 



THE ORIGINAL MAGAZINE FOR 
OWNERS OF THE TRS-80 ™* MICROCOMPUTER 



SOFTWARE 

FOR TRS-80'" 

OWNERS 



H 



CQMPUTRQNICS 

MONTHLY NEWSMAGAZINE 

Practical Support For Model I & II 



i 

N 
C. 



MONTHLY 

NEWSMAGAZINE 

FOR TRS-80'" 

OWNERS 



• PRACTICAL APPLICATIONS 

• BUSINESS 

• GAMBLING • GAMES 

• EDUCATION 

• PERSONAL FINANCE 

• BEGINNERS CORNER 

• NEW PRODUCTS 

• SOFTWARE EXCHANGE 

• MARKET PLACE 

• QUESTIONS AND ANSWERS 

• PROGRAM PRINTOUTS 
AND MORE 



FBtt 



PROGRAMS AND ARTICLES PUBLISHED IN OUR FIRST 12 ISSUES 
INCLUDE THE FOLLOWING: 

A COMPLETE INCOME TAX PROGRAM (LONG AND SHORT FORM) 

INVENTORY CONTROL 

STOCK MARKET ANALYSIS 

WORD PROCESSING PROGRAM (FOR DISK OR CASSETTE) 

LOWER CASE MODIFICATION FOR YOUR VIDEO MONITOR OR PRINTER 

PAYROLL (FEDERAL TAX WITHHOLDING PROGRAM) 

EXTEND 16 DIGIT ACCURACY TO TRS-80'" FUNCTIONS (SUCH AS 

SQUARE ROOTS AND TRIGONOMETRIC FUNCTIONS) 

NEW DISK DRIVES FOR YOUR TRS-80'" 

PRINTER OPTIONS AVAILABLE FOR YOUR TRS-80'" 

A HORSE SELECTION SYSTEM***ARITHMET1C TEACHER 

COMPLETE MAILING LIST PROGRAMS (BOTH FOR DISK OR CASSETTE 

SEQUENTIAL AND RANDOM ACCESS) 

RANDOM SAMPLING***BAR GRAPH 

CHECKBOOK MAINTENANCE PROGRAM 

LEVEL II UPDATES***LEVEL II INDEX 

CREDIT CARD INFORMATION STORAGE FILE 

BEGINNER'S GUIDE TO MACHINE LANGUAGE AND ASSEMBLY 

LANGUAGE 

LINE RENUMBERING 

AND CASSETTE TIPS. PROGRAM HINTS. LATEST PRODUCTS 

COMING SOON (GENERAL LEDGER. ACCOUNTS PAYABLE AND 
RECEIVABLE. FORTRAN-80, FINANCIAL APPLICATIONS PACKAGE, 
PROGRAMS FOR HOMEOWNERS, MERGE TWO PROGRAMS. 
STATISTICAL AND MATHEMATICAL PROGRAMS (BOTH 
ELEMENTARY AND ADVANCED) , . . AND 



WORD PROCESSING PROGRAM (Cassette or Disk) For writing letters, text, mailing lists, etc., with each new subscriptions or renewal. 

LEVEL II RAM TEST (Cassette or Disk) Checks random access memory to ensure that all memory locations are working properly. 

DATA MANAGEMENT SYSTEM (Cassette or Disk) Complete file management for your TRS-I 

CLEANUP (Cassette or Disk) Fast action Maze Game 

ADVENTURE (Cassette or Disk) Adventure #0 by Scott Adams (From Adventureland International) 



F*££ 



• TRS-80" IS A TRADEMARK OF TANDY CORP 



SEND FOR OUR NEW 48 PAGE SOFTWARE CATALOG (INCLUDING LISTINGS OF HUNDREDS OF TRS-80'" PROGRAMS AVAILABLE ON 
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SAMPLE OF LATEST ISSUE $4 

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' ADD S6/YEAR (CANADA, MEXICO) - ADD J12/YEAR AIR MAIL - OUTSIDE OF U.S.A., CANADA & MEXICO ' 



Circle 142 on inquiry card. 



BYTE August 1980 195 



H 



HERE 



{ IF ... ELSE 1 
... THEN } 



KEY 



2-byte variable containing address of the top of the dictionary; execution of this 
word causes the address of the variable H (not its value, which equals the address 
of the top of the dictionary) to be placed on top of the stack. 

Places the address of the next byte to be used in the dictionary (the value of H) on 
top of the stack. 

When executed within a { DO ... LOOP } , the word I pushes onto the 
top of the stack the value of the index counter; for example, 
{ 10 DO I . LOOP } prints the numbers from thru 9. 

Conditional execution of words depending on value of top-of-stack. If nonzero, 
execute words between IF and ELSE . If zero, execute words between ELSE and 
THEN ; for example, { IF " NUMBER ON TOP IS NONZERO" 
ELSE " NUMBER ON TOP IS ZERO" THEN } prints the appropriate message 
depending on the value on top of the stack. 

Gets a single character from the keyboard; for example, if the stack before we 
press the space bar is: 

9 9 3 5 
Then, after we press the space bar (ASCII value decimal 32), the stack is: 

9 9 3 5 32 



MAX 



Compares the two top entries on the stack and leaves only the larger; example: 
before: 9 9 3 5 
after: 9 9 5 



MIN 



Compares the two top entries on the stack and leaves only the smaller; example: 
before: 9 9 3 5 
after: 9 9 3 



MINUS 



Changes the sign of the entry on top of the stack; example: 
before: 9 9 3 5 
after: 9 9 3-5 



OVER 



Copies the second-to-top entry onto the top of the stack; example: 
before: 9 9 3 5 
after: 9 9 3 5 3 



PAD 



SWAP 



PAD is a 2-byte variable that points to the beginning of a 64-byte area for tem- 
porary storage of character strings; execution of this word causes the address of 
this 2-byte variable to be placed on top of the stack. 

Exchanges the two top entries on the stack; example: 
before: 9 9 3 5 
after: 9 9 5 3 



U* 



The lower 8 bits of the two top entries on the stack are isolated and multiplied 
together, leaving their unsigned 16-bit product; example: 

before: 9 9 3 5 

after: 9 9 15 
Each factor will effectively be 255 or less, giving a product that will not overflow 
in 16 bits. 



VARIABLE 



{ 1 } 



Creates a variable that has the value of top-of-stack; example, before executing the 
phrase { VARIABLE VAR } , the stack looks like: 

9 9 -14017 
After the phrase has been executed, the stack looks like: 

9 9 
and the word VAR , when executed, will place the address of the variable on the 
stack. (The 2-byte number stored at that address will contain the value —14017.) 
Unlike a constant, the value of a variable can be changed using { ! } (store). 

Resumes compilation of a colon definition. ■ 



196 August 1980 © BYTE Publications Inc 



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BYTE August 1980 197 



Khachiyan's Algorithm, Part 1: 

A New Solution to Linear 
Programming Problems 



G C Berresford, A M Rockett, and J C Stevenson 

Dept of Mathematics 

C W Post Center, Long Island University 

Greenvale NY 11548 



Editor's Note: 

This two-part article presents some of the most dif- 
ficult mathematics we have ever published in BYTE, 
but we believe that the attention given to the 
Khachiyan algorithm of late warrants a complete and 
rigorous treatment here. Part 2 will contain a linear 
programming example and a TRS-80 BASIC program 
designed to illustrate the algorithm CM 



Khachiyan's Vector Notation 

The vector notation used in Khachiyan's paper is 
different from that used by most Western mathemati- 
cians, so a word of explanation is in order. A system of 
linear equations (or, as in equation (1.1), linear in- 
equalities) can be expressed in the form: 

Ax = b 

where x is a column vector of the variables x x thru x„, b 
is a column vector of the coefficients b x thru b„ (one 
for each of the m equations in the system), and A is an 
m-by-n matrix (m rows, n columns), where each row 
of the matrix A contains the coefficient for the corre- 
sponding equation. Khachiyan's notation expresses 
everything in terms of column vectors. In particular, a, 
is a column vector containing the coefficients of the ith 
equation. But since the coefficient vector must be a 
row vector in order to be multiplied by the column 
vector x, we follow Khachiyan's notation and denote 
the corresponding row vector as dl t where the 
superscript t denotes the transposition of column vec- 
tor a,...GW 



The three-column headline "A Soviet Discovery Rocks 
World of Mathematics" was spread across the bottom of 
the front page of the New York Times for Wednesday, 
November 7, 1979. In the following weeks, subsequent 
articles were heralded as "Shazam! A Shortcut for Com- 
puters" and "Mathematician Is Obscure No More." Over- 
night, Leonid Khachiyan became famous as the author of 
a revolutionary discovery in the field of linear program- 
ming. 

What has Khachiyan accomplished? All of the articles 
in the press are based on second- or third-hand reports 
and interpretations. [In fact, the first New York Times 
article incorrectly heralded the discovery as a solution to 
the still-unsolved "traveling salesman" problem.... GW] 
Lynn Steen's article in Science News, "Linear Program- 
ming: Solid New Algorithm," (October 6, 1979) and Gina 
Bari Kolata's article in Science, "Mathematicians Amazed 
by Russian's Discovery," (November 2, 1979) discuss the 
basic problem of linear programming and then report on 
a paper by Peter Gacs and Lazslo Lovasz that^ discusses 
Khachiyan's algorithm. The Gacs and Lovasz paper 
opens with the statement "we have ignored his 
[Khachiyan's] considerations which concern the precision 
of real computations..." and then proceeds to describe a 
modification of Khachiyan's algorithm, although the dif- 
ferences between the two procedures are never made ex- 
plicit. 

The notation used in this article, although explained in the text, 
deserves some attention. In particular, the distinction between boldface 
and italics is an important one. An italicized variable refers to a scalar 
quantity (eg: x r =3). A variable in boldface refers to a column vector or 
a matrix. For example, in the equation Ax=b, A is a matrix and x and b 
are column vectors. 

Also, although this article is based on a paper written by Khachiyan, 
his discovery was not made without the benefit of previous work by 
other men. Khachiyan's paper is based on earlier work by A Yu Levin, 
N Z Shor, D B Judin, and A Z Nemirovsky....GW 



198 August 1980 © BYTE Publications Inc 



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BYTE August 1980 199 



This article will present a summary of and a commen- 
tary on Khachiyan's original paper. A graphic example of 
how the algorithm works is shown in figure 3. We will 
show how Khachiyan's method handles linear program- 
ming problems and discuss some possible improvements 
in the computer application of Khachiyan's proposals. 
We will then turn to the practical question: Is 
Khachiyan's algorithm capable of immediate computer 
application? Although our conclusion is a qualified "no," 
we will discuss a BASIC program (in Part 2 of this article) 
for the TRS-80 that can be used to gain an appreciation of 
Khachiyan's achievement. 

Khachiyan's Paper 

Our discussion of Khachiyan's paper is based on B 
Seckler's translation of the paper into English. We would 
like to thank Professor Seckler for making this transla- 
tion for us. We use Khachiyan's notations in this discus- 
sion so that what he did and how he described it will be 
clear. 

Consider the regions of the plane R 2 shown in figure 1. 
The region in figure la is the intersection of the four half- 
planes Xi>l, *i<2, * 2 ^1, and * 2 <2. These inequalities 
may be rewritten in the form: 



~X\ + 0* 2 < -1 

*i + 0* 2 < 2 

0*i - x 2 < -1 

0*i + x 2 < 2 



(1.1) 



*1 + 0* 2 < 


1 


0*i + * 2 < 


1 


-*1+ 0*2 ^ 


-2 


0*1 - * 2 < 


-2 



Since there are points in the plane that satisfy all four 
inequalities at once, this system of linear inequalities is 
said to be consistent. 

In figure lb, the shaded region on the lower left-hand 
side is defined by *i<l and * 2 ^1, while the shaded 
region on the upper right-hand side is given by * x > 2 and 
* 2 ^2. If we combine these inequalities into one system: 



(1.2) 



we notice that there is no point in the plane that satisfies 
all four inequalities at once. Such a system of linear 
inequalities is said to be inconsistent . 

We shall use the letters a, b, ... to denote column vec- 
tors and a' to denote the transposition of the column vec- 
tor into a row vector. (See text box.) We will write R" for 
the usual re-dimensional Euclidean space. [Readers un- 
familiar with vectors and matrices will find descriptions 
in many engineering mathematics texts. Advanced 
Engineering Mathematics by E Kreyszig, Wiley, 1967, 
2nd ed, is particularly good.... CM] 

Using the above notation, we may let x' = (* : , * 2 ), ai 
= (-1,0), a 2 = (1,0), a^ = (0,-1), and a; = (0,1). Then 
(1.1) may be rewritten in the form: 

a;«x < bi (for i = 1,2,3,4) 

where b-i = —1, b 2 = 2, b 3 = —1, and fo 4 = 2. 

As we see from figure 1, such a system of linear in- 
equalities may or may not be consistent. We will consider 



only inequalities in which all coefficients are integers. 
This is no loss of generality, since numbers in a computer 
can be expressed only to a fixed number of decimal 
places. By multiplying each inequality through by an 
appropriate power of ten, we may express each inequal- 
ity in integers alone. 

Thus we are led to the following problem. Given a 
system of linear inequalities: 



a/«x < b t for i = \,...,m 



(2) 



with integral coefficients, is the system consistent or 
inconsistent? 

Advantages of Khachiyan's Algorithm 

Khachiyan's algorithm is a procedure for deciding 
whether the system given in (2) is consistent. In addition, 
if the system is consistent, it finds the coordinates of a 
point satisfying all of the inequalities, or it at least deter- 
mines them within a small margin of error. Furthermore 
— and this is the "revolutionary" aspect — the method 
gives at the start a maximum number of steps (each step 



(a) 





Figure 1: Consistent and inconsistent systems of linear inequal- 
ities. The shaded area in figure la represents the solution set of 
the four inequalities, Xi>l, x^<2, x 2 >l, x 2 <2. Since points 
exist that satisfy all four inequalities, the system is said to be 
consistent. The system shown in figure lb is inconsistent. The 
lower shaded area is given by the equations x x < 1 and x 2 <l; the 
upper shaded area is given by ;ti>2 andx 2 >2. No point satisfies 
all four inequalities simultaneously. 



200 August 1980 © BYTE Publications Inc 



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BYTE August 1980 201 



requiring a fixed number of mathematical operations) 
that will be required to solve the problem. This maximum 
number of steps increases as the number of variables in 
the problem increases. With Khachiyan's method, 
however, the maximum number of steps grows far more 
slowly than with any other known method, as will be 
described shortly. 

For a system given by (2), let: 



L = 



m n 

L £ 
1=1 



log 2 (|«{|+l) + 



LU=i ;=i 



m 

£ log 2 ( 
i = 1 



b t \ +1) + \og 2 nm 



+ 1 



(3) 



where []VJ denotes the greatest integer less than x. This 
quantity gives a measure of the size of the system (2) of 
inequalities and an estimate of the number of binary sym- 
bols (0 and 1) needed to pose the system for Turing 
machine solution. 

The execution of the algorithm involves N = 16Ln 2 
iterations. The values computed at each step are required 
to be accurate to 2' 37 " L . Notice that as the system of in- 
equalities is made more and more complicated, the 
number of steps in the algorithm increases as a 
polynomial in n. This means that the problem of deter- 
mining the consistency of a system of linear inequalities 
belongs to the class of problems that are solvable in 
polynomial time on deterministic Turing machines. But 
from a practical viewpoint, it must be noted that the 
precision required also increases tremendously with the 
size of the problem. 

[The phrase "solvable in polynomial time" means that 
the time (or amount of computation) necessary to solve 
the problem is always less than a certain computable 
amount. The amount is computed by evaluating a func- 
tion of n, the number of variables in the problem; and 
when the problem is solvable in polynomial time, the 
function uses only powers of the function (eg: time t = K„" 
for Khachiyan's algorithm, for some very large value of K 
and some constant value p). This is an advantage when 
solving a linear programming problem because existing 
methods solve the problem in exponential time (a func- 
tion that uses the term e"), and, for a sufficiently large 
value of n, a solution in exponential time will take much 



longer than a solution in polynomial time. To date, the 
extremely high computation time has made computer 
solution of very large linear programming problems im- 
possible. The significance of Khachiyan's algorithm being 
computable in polynomial time is that, on the surface, it 
opens the possibility of computer solution of these prob- 
lems.... GW] 

Details of the Algorithm 

The steps of the algorithm involve four quantities: a 
vector x k in R" representing the estimate of a solution at 
the conclusion of the fcth iteration; an n-by-n matrix, Q fc , 
representing the dimensions of an ellipsoid containing the 
solutions of the system; the current discrepancy 6 k (x k ) 
which measures how far the current estimate % k is from 
being a solution; and the discrepancy of record, Q k , 
which keeps track of the best estimate of a solution found 
so far by being equal to the smallest 6 value encountered 
within its first k values. 

The principle of the algorithm is like the traditional 
method of catching fish in a net: casting the net over such 
a large region that some of what is wanted must be inside, 
then gradually decreasing the volume of the net. When 
the volume is sufficiently reduced, it becomes obvious 
whether or not anything has been caught. 

At the initial step, k = 0, we set: 



x = 

Qo = 2 L X I„ 

©o = do (x ) = max (bi) 

i 

(where I„ is the n-by-n identity matrix) 



(4) 



The execution of the algorithm at the /cth step begins 
by finding the current discrepancy 

d k (xj = max (a! • x k —b t ) 

i 

and recording the value of i (labeled i(k)) of the equation 
giving this maximum value. 6 k measures the discrepancy 
of the current x k from being a solution of (2), while i(k) 
specifies the index of the inequality that is the worst of- 
fender. The discrepancy of record, 9 k+ i, is defined as the 
minimum of Q k and 6 k (x k ). 



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REM MERGE SORT USING LINK FOR INDEX 
FUNCTION MERGE (1,1 = INTEGER) -INTEGER 
VAR T,KM,M = INTEGER 
IF ARRAY (I) <ARRAY (J) THEN 
BEGIN 

M=I 
1=J 






I 



WfflLEIOODO 

BEGIN 

IF ARRAY (1) <ARRAY (!) THEN 
BEGIN 

' M=t 
1=1 
J=M 
END 

LINK(KM)^I 

KM = 1 

I-LINK(l) 
END 

LINK(KM) = I 
END=T 

FUNCTION SORTUS.IS = INTEGER) - INTEGER 
VARKS.IUJ INTEGER 
IF IS = IS THEN 
BEGIN 

LINK(IS) = 

RETURNED VALUE = IS 
GOTO OEND 
END 
KS = IS+((IS -IS) 2) 
II SORT(IS.KS) 
II=SORT(KS+l,IS) 
RETURNED VALUE MERGE(II,IJ) 
OEND END RETURNED VALUE 





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The algorithm then shifts the center of the ellipsoid net 
in the "direction" of i(k) and shrinks the ellipsoid to close 
in on the desired solution. (See figure 3 and the following 
geometric interpretation of the algorithm in the text.) 
This is accomplished by setting: 



Xjt+i — x* H 



Q t -F* 



n+1 |F fc | 



(5) 



Q k+ . 



2 l/(8n>) x Qk . Qrt (Ft) . An 



where: 



F t = -QE • a„ t) 

I F k I is the norm (or magnitude) of the column 
vector F* 

Ort (F fc ) is an orthogonal n-by-n matrix (con- 
structed by the Gram-Schmidt process) with the 
first column equal to F*/JF*| (remember that, 
because of its orthogonality, Ort(F^) is a distance- 




Figure 2: A set of linear inequalities. The shaded area represents 
the solution set of the two inequalities, x^>l and z 2 > 2. Figure 3 
shows how Khachiyan's algorithm solves this system of linear 
inequalities. 



preserving linear transformation) 
• A„ is the n-by-n diagonal matrix with diagonal en- 
tries (n/(n + l)), (n/Vn^T), ... , (nA/n^T) 

It is possible to show by induction that the sizes of the 
quantities in (5) obey the following constraints: 



x* 



<4k2 ,8£ 



10*1 *2* 

^ det(QJ 



(6) 



where the norm of matrix Q k ( || Q k \\ ) is the square root of 
the sum of the squares of its entries. It is important to 
note that the point x k generated by this algorithm may 
jump around in a rather random and sometimes ex- 
travagant manner, and that it is only the steady contrac- 
tion of the region (which has a volume equal to det (Q*)) 
that ensures that a solution will ultimately be found. 

If 6 k (x t ) becomes zero or negative at any step, then x* is 
a solution of the system (2), and the algorithm is ter- 
minated. If the algorithm runs through all N. = 16Ln 2 
steps, the discrepancy 0jv +1 is calculated and the process 
ends. 

Geometry of the Algorithm 

Geometrically, each solution x for the system (2) of in- 
equalities can be considered as a point in n-dimensional 
space, and the aggregate of all such solution points forms 
a certain volume, the solution set. In Khachiyan's 
algorithm, each matrix Q k specifies an ellipse E k centered 
at the point % k according to E k = [y: y = x* + Q*z, |z| 
< 1]. [A less formal description of E k is as follows: the 
n-dimensional ellipse E k is the set of points (or column 
vectors) y that are formed by adding the column vector 
Q t z to the current estimate \ k , where z is an arbitrary 
n-dimensional column vector with a length (magnitude) 
of 1 or less.... GW] 

The initial choice of x and Q specifies a sphere of 
radius 2 L centered at the origin. It can be shown that this 
sphere contains at least a certain minimum volume of 
solution points, if any exist. The ellipses then change 
position and shrink, but they always contain at least the 
prescribed minimum volume of solutions. Khachiyan's 
observation is that, once the ellipse has shrunk to that 



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Circle 71 on inquiry card. 



BYTE August 1980 205 



(a) 




(b) 



Figure 3: A graphic example of Khachiyan's algorithm. The 
Khachiyan algorithm (described here for a two-dimensional 
problem) begins with a circle centered at the origin with a radius 
of a given size such that the circle is guaranteed to contain the 
solution points, if they exist. Successive iterations of 
Khachiyan's algorithm produce ellipses of smaller area that still 
contain the solution points. Here, the initial circle E is shown in 
figure 3a. Ellipse E[ is then computed from E , as shown in figure 
3b, and ellipse E' 2 is computed from E[, as shown in figure 3c. In 
the last two figures, the current ellipse is shown in black, and the 
previous ellipse is shown in gray. The shaded area in all three 
figures describes the inequalities' solution set. 



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minimum volume (and it does so within 16Ln 2 steps), it 
can contain only solutions. Thus, either the center x k is a 
solution (making the discrepancy < 0), or there were no 
solutions in the first place, and the system is inconsistent. 
To see graphically how the ellipses evolve, we will con- 
sider the following simple system of linear inequalities: 

— Xt + 0;c 2 < —1 
Ox, - x 3 < -1 

graphed in figure 2. These are, in fact, the first and third 
inequalities of system (1.1). 

To make the diagrams clearer, we do not take L = 7, 
as equation (3) would dictate, but L = 2, which we will 
later show (in Part 2) is permissible. This makes x = 
and Q = diag(4,4) (a 2-by-2 matrix with 4 in the main 
diagonal elements, elsewhere). The initial ellipse E is 
shown in figure 3a. 



206 August 1980 © BYTE Publications Inc 



Circle 148 on inquiry card. 



THE 6502 BOOK YOU'VE WAITED FOR. . 



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Khachiyan's algorithm is an approximation of the 
following geometric construction of the next ellipse E k+ i 
with center x t+I from the known ellipse E k with center x k . 
Since this construction does not give the exact results of 
the formulas in (5), we will denote the results of our con- 
struction by E' k +i and x*+i. 

The ellipse E{ is determined from E and x (see figure 
3b) as follows: 

• Draw a chord through x parallel to the boundary 
of the inequality most severely violated (indicated 
previously as having subscript i(k)). This chord 
cuts the ellipse E at two points, pi and p 2 . The 
solution set of the inequality i(k) will lie on one 
side, the "solution side," of the chord. (The solu- 
tion side of the hyperplane can be determined by 
examination.) 

• The new ellipse E{ passes through p! and p 2 , has 
its center on the solution side of the chord, and is 
tangent to the old ellipse £ at the point T. 

• Of the infinite family of ellipses satisfying the 
above conditions, choose the one with the 
smallest volume. \{ is the center of this new 
ellipse E{. 

The ellipses E{ and E' 2 (determined similarly from E{) 
are shown in figures 3b and 3c, each with its predecessor 
drawn in gray. Note that the ellipses are shrinking, the 
three having approximate areas of fifty, forty, and thirty- 
two square units respectively. The algorithm ended with 
ellipse Ei, since its center x' 2 is in the solution set. 

It is important to notice that, while the requirements of 
tangency and minimal volume in our construction are 
aesthetically pleasing, they are impossible to achieve in 
practice. Remember that Khachiyan is concerned with a 
calculation procedure having only a limited degree of ac- 
curacy. If any of the numbers encountered in the execu- 
tion of the algorithm could not be exactly represented in 
the computer, the cumulative effect of the resulting 
roundoff errors could be fatal, particularly in the detec- 
tion of the inconsistency of a system of inequalities. The 
paper of Gacs and Lovasz, mentioned previously as ig- 
noring questions of computational precision, presents a 
modification of the algorithm that computes the tangent 
ellipses of minimal volume. Thus the Gacs-Lovasz for- 
mulas cannot be expected to be successful in any actual 
computation. 

Khachiyan overcomes this difficulty by choosing his 
ellipses slightly larger than necessary so that, even with 
his limited accuracy, he can assure that the region he 
wants is contained in them. The trick here is that if the 
ellipses are made too large, they will not shrink down on 
the solutions fast enough. Khachiyan's formulas in (5) for 
the ellipses achieve the proper balance between the prob- 
lem of accuracy and the need for a rapidly shrinking 
series of ellipses. 

If you carry out the calculations for the example of 
figure 2, you will find that, while E{ passes through the 
points (O, 4)' and (4, O)', Khachiyan's ellipse E t passes 
through (0, 4.12)' and (4.06, 0)*. 

Part 2 of this article will discuss a fundamental short- 
coming of Khachiyan's algorithm and will include a pro- 
gram in BASIC for the TRS-80. ■ 



208 August 1980 © BYTE Publications Inc 



Circle 150 on inquiry card. 



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Construction of a Fourth- 
Generation Video Terminal, Part 1 



Theron Wierenga 

POB 2007 
Holland MI 49423 



The construction of this fourth- 
generation video terminal is a project 
that began as a detour from the plans 
for building a 16-bit microcomputer. 
I have had a long-standing interest in 
building an advanced-design video 
terminal that would have a scrolling 
feature and a large 2000-character 
display. It was my desire to have the 
terminal utilize one of the new pro- 
grammable video-display-controller 
integrated circuits, and be a stand- 
alone unit with its own micropro- 
cessor that would not steal cycles 
from or otherwise load down the 
host computer. The number of addi- 
tional parts that are needed to add the 



microprocessor is quite minimal and, 
in turn, the microprocessor reduces 
additional interfacing that would be 
otherwise needed. The circuitry of 
this terminal, when wire-wrapped on 
a single board, could fill one slot in 
the motherboard of the planned 
16-bit microcomputer, or could be 
used with any other host computer as 
a stand-alone unit. 

Upon receiving a copy of Intel Cor- 
poration's Peripheral Design Hand- 
book (April 1978 edition), I found a 
set of plans for just such a terminal. 
The article is entitled "CRT Terminal 
Design Using the Intel 8275 and 
8279." This circuit and its associated 
software were the basis for my 
design. This month, in Part 1, I'll 
describe the construction up to the 
point where you can get the 8085 
microprocessor operating. Next 



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month, in Part 2, 1 shall tell about the 
procedures for assembling the 
keyboard and video circuitry, putting 
the control software into operation, 
and checking out the system. Readers 
planning to build this terminal should 
obtain a copy of the Peripheral 
Design Handbook, as well as the 
MCS-85 Users Manual, which 
describes the operation of the 8085 
microprocessor. Included in the fifty- 
seven-page article are detailed design 
theory, system specifications, system 
hardware and software design, an ex- 
planation of software subroutines, 
and the original design schematics 
and data sheets on the Intel peripheral 
circuits that are utilized in the design. 
The Intel handbooks are available 
from Intel Corporation, Literature 
Department, 3065 Bowers Ave, Santa 
Clara CA 95051. 

Terminal Features 

Here are some of the features of 
this video terminal: 

Display format: eighty characters 
per display row, twenty-five 
display rows. 

Character format: 5-by-7 character 
contained within a 7-by-10 matrix, 
first and tenth lines blanked, first 
and seventh columns blanked, 
ninth line cursor position, blinking 
underline cursor. 

Character recognized: Displayable 
characters: sixty-four American 
Standard Code for Information In- 
terchange (ASCII) uppercase 
alphanumeric characters, 
Control characters: 
Line feed (control-J), 
Carriage return (control-M), 
Back space (control-H), 
Escape sequences: 
Cursor up (ESC, A), 
Cursor down (ESC, B), 
Cursor right (ESC, C), 
Cursor left (ESC, D), 
Clear screen (ESC, E), 
Home (ESC, H), 
Erase to end of screen (ESC, 

J), 
Erase line (ESC, K). 
Characters transmitted: sixty-four 



210 August 1980 © BYTE Publications Inc 



Circle 152 on inquiry card. 



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COLLECTOR 




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Robert Tinney Graphics is now issuing 
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o 



ASCII uppercase alphanumeric 
characters, ASCII control 
character set, ASCII escape 
sequence set. 

Program memory: 2 K bytes, 2716 
erasable programmable read-only 
memory. 

Display/buffer/stack memory: 
2 K bytes, 2114 static program- 
mable memory. 



Data rates: 300, 600, 1200, 2400, 
4800 bits per second (bps). 
Interface to host computer: 20 mA 
current loop. 

Scrolling capability: Scroll-up 
feature implemented with 8257 
direct-memory-access controller. 
The author of the Intel article used 
an 8080A-based single-board com- 
puter, the Intel SDK-80, and an 




Photo 1: The complete video terminal circuitry constructed on a wire-wrap board. The 
component side is shown. 



* i WIIINC JIM 'JSH L- 




Photo 2: The bottom or wired side of the video terminal board. 



SBC-905 prototype board for the 
additional circuitry needed. I wanted 
everything to fit on a single board 
and to run off a single 5 V power sup- 
ply, so extensive changes were made 
in my design. The schematic diagram 
appears in figure 1. The completed 
unit retains all of the original features 
plus one or two more. 

Hardware Changes 

The following are the major hard- 
ware changes that were made in my 
design: 

• An 8085 microprocessor was 
substituted for the 8080A device. 
Although the parts count is about 
the same, the 8085 system needs 
only a single 5 V power supply. 
The 8085 microprocessor needs an 
additional 8212 latch for the lower 
address lines and a 74LS257 multi- 
plexer to produce the control bus. 
The interfacing to the 8257 direct- 
memory-access controller is some- 
what involved; a detailed 
schematic of this is provided in the 
Peripheral Design Handbook on 
pages 1 thru 82. 

• The ad ditional 8216 bu ffer from 
MEMR and MEMW is un- 
necessary. These signals can be 
taken directly from the 74LS257. 

• A single 74LS138 decoder was used 
for enabling the peripheral cir- 
cuitry (ie: the 8251, 8257, 8275, 
and 8279 devices). 

• A 5 V type, 2513 character- 
generator read-only memory was 
substituted for the 2708. This saves 
programming the sixty-four 5-by-7 
matrices into a 2708-type program- 
mable read-only memory. 

• The MD (mode) lines on the two 
8212s that buffer the 2114 memory 
integrated circuits are tied to 
ground instead of +5 V. This is 
an error in the Intel schematic. 

• Interrupt lines for the 8251 and 
8275 are not connected into the 
8085. The TRAP interrupt is pulled 
down to ground through a dual-in- 
line pin (DIP) switch. Opening this 
switch pulls up the TRAP inter- 
rupt, vectoring the 8085 micropro- 
cessor to a small system monitor. 

• Video and sync signals were added 
together through the use of a 7401 
open-collector NAND package 
and a single transistor to form a 
composite-video output. 

Text continued on page 216 



212 August 1980 © BYTE Publications inc 




Let this New Series from 

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Programming Techniques is a series of 
collected articles concerned with the art and 
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volume in the Programming Techniques 
series is entitled Program Design. The pur- 
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ISBN 0-07-037825-8 Pages: 96 
Price: $6 
Editor: Blaise W. Liffick 

Simulation is the second volume in the 
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ISBN 0-07-037826-6 Pages: 126 
Price: $6 
Editor: Blaise W. Liffick 

Numbers in Theory and Practice is the 
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ISBN 0-07-037827-4 Pages: 192 

Price: $8.95 

Editor: Blaise W. Liffick 

The 4th volume of the Programming 
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ISBN 0-07-037828-2 Pages: 160 
Price $8.95 
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SERIAL INTERFACE 




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Figure 1: Schematic diagram of the video terminal circuit. The Intel 8275 video-display controller is in the center of the figure. 

214 August 1980 6 BYTE Publications Inc 




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August 1980 © BYTE Publications Inc 215 



Text continued from page 212: 

• With a system clock of 6.144 MHz, 
data rates of 300, 600, 1200, 2400, 
and 4800 bps were generated with 
a 7490 and 7493 counter. Data-rate 
selection is through five positions 
of an eight-position DIP switch. 

• A current-loop interface was used, 
since only a 5 V supply was 
available. There is also provision 
for direct access to the universal 
asynchronous receiver /transmitter 



(UART) pins. 

An 8131 comparator was 
substituted for the 74LS138 used 
for 2716 decoding. 
Decoding was done somewhat dif- 
ferently for the programmable 
memory, although the addresses 
still extend from hexadecimal 8000 
to 87FF. These addresses make 
compatability with the 8257 direct- 
memory-access controller easy. 
Details are given as to how the 



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\»~*'\ f«Q-' fw" ^ p$ V V ( ! 9*| N<| W j»N ' r \ "'" m "* 

M |M) M W W W Ml M M Nl I'M ri*l Ns ''I; v «*— 4 
^ ^im^ i^z i H N M N N i M i N ^ W" I "'" I N 



Photo 3: The sixty-three-key Jameco keyboard mounted on its printed-circuit board 
and installed on support blocks. 



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keyboard is connected to the 
system. This is missing in the 
original article. An inexpensive 
unencoded keyboard (available 
from Jameco Electronics) was 
mounted using a printed-circuit 
board as well as some wire-wrap 
connections. 

• The video monitor that I used is a 
12-inch Motorola unit that takes a 
composite-video input signal. It 
was obtained as surplus in used 
condition. Whatever brand or size 
is used, it should have a bandwidth 
of 12 MHz. 

Software Changes 

A number of changes were made in 
the software as supplied in the Intel 
articles. Several minor changes have 
no direct effect on the program execu- 
tion, but rather just shorten the code. 
The major changes are as follows: 

• The interrupt vectors at the top of 
the program were removed. A 
single vector for the TRAP inter- 
rupt was left in. When the TRAP 
switch is opened, the 8085 
microprocessor will transfer con- 
trol to a small system monitor that 
can be used for debugging. 

• A polling system is used in place of 
the interrupt system to check the 
states of three of the peripheral 
systems. First, the system checks to 
see if a character has been received 
by the 8212; second, if the 8275 has 
requested that the 8257 be 
reinitialized; and third, if the 8279 
has a character to be transmitted 
from the keyboard. A data rate of 
4800 bps is still possible using this 
polling system. 

• The table for character lookup for 
the keyboard has been changed 
completely. This was done to com- 
ply with the way that I had wired 
the scan matrix for the unencoded 
keyboard. A few additional ASCII 
codes were added that can be 
transmitted from the video ter- 
minal. These codes were for keys 
on the Jameco keyboard. 

• The initialization of the 8251 and 
8279 was changed. The values used 
should work for most systems. 

• The 8257 was initialized to Mode 
because of the change to a stan- 
dard 2513 character generator. 

• A system monitor was added at the 
bottom of the program which has 
five commands. The use of the 
monitor is covered in Part 2 of this 
article. 



216 August 1980 © BYTE Publications Inc 



Circle 153 on inquiry card. 



Circle 154 on inquiry card. 



Circle 155 on inquiry card. 



16 BITS100 PROCESSOR 

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BYTE August 1980 217 




Photo 4: The etch side of the keyboard circuit board, showing the jumper connections 
made necessary by use of the single-sided board. 



• The port numbers for the 
peripheral circuits have been 
changed. These values are set at 
the beginning of the video-control 
software. 

Construction 

The order in which the sections of 
this video terminal are built is very 
important. It is most unusual to put 
together a project as complex as this 
without having some sort of pro- 



blems. Following the order as it is 
given here will help with some debug- 
ging, and hopefully make things go 
more easily. Do not try to assemble 
everything and then give it the smoke 
test. 

I chose to connect the electronic 
parts by wire-wrapping. With the 
hundreds of connections necessary, it 
is almost impossible to not make a 
few wiring errors the first time 
around. Wire-wrapping allows you 




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to add or change connections easily if 
it is necessary. Wire-wrap also allows 
for a very compact design, which 
helps to cut down the electrical noise 
in the system. You should have 
available an oscilloscope, frequency 
counter, a general-purpose volt-ohm 
milliammeter, a wire-wrap gun, 
30-gauge wire strippers, and a 
quantity of 30-gauge wire ias well as 
the usual pliers, screwdrivers, solder- 
ing iron, etc). 

A large Vector wire-wrap board 
(#4350) was used for the circuit, but 
several other general-purpose wire- 
wrap boards could also be used. 
Some individuals may choose one of 
the S-100 type boards, which would 
work just as well. Use one that has 
power and ground planes on it. This 
makes it easy to distribute the power 
supply lines to integrated circuits, 
and provides a good method for in- 
stalling noise capacitors. 

Glue the integrated-circuit wire- 
wrap sockets in place with an epoxy- 
type glue that comes in two com- 
ponents and must be mixed before 
use. After mixing the adhesive, wait 
until it starts to thicken considerably 
before applying it to the sockets. If 
the integrated-circuit sockets that you 
use do not have a few small holes in 
the bottom of the plastic body, make 
two or three holes with a 1/16-inch 
drill. This will give the glue 
something to which it can adhere. Do 
not use any of the "super glue" types 
of instant-bonding adhesive, as these 
are very thin and can bleed into the 
integrated-circuit socket, plugging up 
the pin holes and cementing the con- 
tacts together. An illustration of the 
parts layout is shown in figure 3. 

Following my own particular 
order, I first make all connections to 
the power-supply pins on the in- 
tegrated circuits. These connections 
are given in table 1. Connect 5 V to 
the power-supply bus and check out 
the voltage at the proper pins of each 
integrated-circuit socket before in- 
stalling the integrated circuits 
themselves. When you do apply 
power to the circuit, have an am- 
meter connected to your power 
supply. High current readings are a 
quick indication of serious problems. 
The entire circuit when completed 
should draw about 1.6 A at 5 V. The 
usual precautions against static elec- 
tricity when handling metal-oxide 
semiconductors (MOS) should be 
observed for the memory circuits, as 



218 August 1980 © BYTE Publications Inc 



Circle 157 on inquiry card. 



Circle 158 on inquiry card. 



Circle 159 on inquiry card. 



IBM + CP/M + OSM 

= CP/M Compatible Distributed Processing 

Multi-User Computer System 




O S M Computer Corporation is introducing a true multi-user, multi- 
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Hardware features Software Features 



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5. Users can select either host or 
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7. Up to 128 user terminals. 

8. Each user has a hardware CPU 
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Use of CP/M 2.2 allows any CP/M 
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DPOS/2 multiuser supervisor ex- 
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2 file protect modes (in addition 
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Dealer Inquiries Invited 



At last-. -the 

Typewriter Interface! 





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5. Same interface for TRS-80, Apple and GPIB. Centronics and Pet 
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Delivery: stock to 2 weeks. Price: $499.00, FOB Rochester, Do- 
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Put your computer 
in touch with the world. 

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historically over 35,000 hours mean time 
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And now, the A 242 from AJ, refur- 
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Bell 103/113 compatible, the originate- 
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California residents call: 
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^Details on request. 




Prices subject to change without notice 



Circle 160 on inquiry card. 



BYTE August 1980 219 



well as all of the 8000-series Intel 
circuits. 

Next, make a photocopy of the en- 
tire schematic diagram. As you begin 
to wrap connections, use a red pen to 
trace each connection made on the 
schematic. This simple method 
eliminates the need for a wiring table, 
but establishes a complete bookkeep- 
ing system that indicates which con- 
nections are installed or incomplete. 

It is helpful to use as many different 
colors of wire as possible. The ad- 
dress bus can be done in one color, 
the data bus in another, power- 
supply lines can be red for +5 V and 
black for ground, and so forth. This 
is a great help when you have to trace 
down wires to check connections. 
Take the time to cut each wire to the 
exact length needed. Do not make 
wires any longer than necessary. 
Route wires neatly in between the 
wire-wrap sockets, and try to keep 
the interior portion of the socket area 
free from bundles of wires. A neat 
board is much easier to troubleshoot 
than the "rat's nest" variety. 

The few resistors and capacitors 
that are needed can be mounted on 



one 16-pin and one 24-pin header 
plug. The 22.68 MHz crystal and 
2N3710 transistor can also be 
mounted on the 24-pin header plug. 
The 6.144 MHz crystal with its two 
20 pF capacitors is mounted next to 
the 8085 with Vector T-49 Klipwrap 
pins. 

Getting the 8085 
Microprocessor Operating 

The first integrated circuits to in- 
stall are the 8085 (ICl), 8212 (IC2, 
low address latch for the 8085), 
74LS257 (IC28), 8131 (IC35), 2716 
(IC34), 8251 (IC7), 74LS138 (IC18, 
peripheral decoder), 7490 (IC16), 
7493 (IC17), the eight-position DIP 
switch, and ICll (the 7400 NAND 
package that contains a gate to buffer 
the clock output of the 8085). All of 
the connections should be made to 
these devices. Program the 2716 read- 
only memory with the 22-byte 
checkout program that is given in 
listing 1. Temporarily ground the 
HOLD input to the 8085 (pin 39) and 
three of the inputs that are normally 
driven by the AEN output (pin 9) of 
the 8257. These inputs are at pin 4 of 




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TinyX" $ 69/$40 

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Magic Wand $299/345 

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Pearl (level 2) $299 

Pearl(level3) $549 

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S-Basic Compiler. . . . $229/325 

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Visicalc" $122 

CCA Data Mgr $86 

Desktop/Plan 3 86 

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IC18 (the 74LS138 peripheral 
decoder), pin 1 of IC2 (the 8212 latch 
that holds the low address lines from 
the 8085), and pin 15 of IC28 (the 
74LS257). 

After you reset the 8085 
microprocessor, the simple test pro- 
gram should send out continuous 
ASCII "U" characters from the 8251 
transmitter data output (pin 19). 
With the 300 bps switch closed, pin 
19 of the 8251 should produce a 
square wa ve at 150 Hz, which is 300 
bps. The IOW line (pin 12 of the 
74LS257) should show 30 Hz on a fre- 
que ncy c ounter. The negative pulses 
on IOW are very narrow and may 
not show up on an inexpensive 
oscilloscope. If you have these signals 
present, your 8085 microprocessor 
and its associated circuitry are work- 
ing correctly. 

Do not go beyond this point in con- 
struction until your 8085 
microprocessor is functioning cor- 
rectly. If you have problems, check 
the following items. Make sure that 
the clock output of the 8085 is 3.072 
MHz, and that this signal is getting to 

Text continued on page 224 



Number 


Type 


+ 5 V 


GND 


IC1 


8085 


40 


20 


IC2 


8212 


24 


12 


IC3 


8212 


24 


12 


IC4 


8212 


24 


12 


IC5 


8212 


24 


12 


IC6 


8224 


16 


8 


IC7 


8251 


26 


4 


IC8 


8257 


31 


20 


IC9 


8275 


40 


20 


IC10 


8279 


40 


20 


IC11 


7400 


14 


7 


IC12 


7400 


14 


7 


IC13 


7401 


14 


7 


IC14 


7410 


14 


7 


IC15 


7474 


14 


7 


IC16 


7490 


5 


10 


IC17 


7493 


5 


10 


IC18 


74LS138 


16 


8 


IC19 


74LS138 


16 


8 


IC20 


74LS138 


16 


8 


IC21 


74163 


16 


8 


IC22 


74166 


16 


8 


IC23 


74175 


16 


8 


IC24 


74175 


16 


8 


IC25 


74175 


16 


8 


IC26 


74175 


16 


8 


IC27 


74175 


16 


8 


IC28 


74LS257 


16 


8 


IC29 


2114 


18 


9 


IC30 


2114 


18 


9 


IC31 


2114 


18 


9 


IC32 


2114 


18 


9 


IC33 


2513 


24 


10 


IC34 


2716 


24 


12 


IC35 


8131 


16 


8 


Table 1: 


Power connections foi 


the in- 


tegrated 


circuits in 


the sc 


lematic 


diagram 


of figure 1. 







220 August 1980 @ BYTE Publications Inc 



Circle 161 on inquiry card. 



Circle 162 on inquiry card. 





Disc/3 

MART, INC. 

DO IT YOURSELF 

LOW-LOW PRICES 

ANADEX PRINTER, DP-8000 $ 825.00 

ANADEX PRINTER, DP-9500 1,425.00 

BASE II Printer (complete with options) 645.00 

CENTRONICS 730 Matrix Printer 745.00 

(with 4 free zip pack) 

HAZELTINE 1520 . ..' 1,319.00 

NEC Spinwriter 5510 (RO) 2,643.00 

SOROC 10. 120 750.00 

SOROC IQ 140 Assembled 1,225.00 

Tl 810 Basic (upper & lower case) 1,669.00 

Tl 994 Personal Computer 1,150.00 

LA 34 DEC Writer Teleprinter 1 ,195.00 

CARTRIDGES • DISKETTES • MAG TAPE • ACCESSORIES 

ADDS, CENTRONICS, HAZELTINE, IMSAI, LEAR SIEGLER, 
TECHTRAN, Tl, VECTOR GRAPHICS AND OTHERS 

STORE HOURS: 9 A.M. -5:30 P.M. Mon. through Fri. 

Call or write for quotes or information. 

Circle 129 on inquiry card. 

1840 LINCOLN BLVD., 
SANTA MONICA, CA 90404 
MART, INC. (213)450 5911 



Circle 163 on inquiry card. 



Disc/3 



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$685 



SYSTEM 



The world's most popular microcomputer, with 16K of 
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Radio /hack 



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Introducing the Ultimate 
Personal Timesliare Network 
and the Star Modem 



Now Available for Pet IEEE 
and KS232C Ports 



Now for the first time ever you 
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Imagine access to an ever 
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The Star Modem, the market's 
most sophisticated acoustic coupler, is 
compatible with standard RS232C 

Circle 164 on inquiry card. 




ports. An 

exclusive triple 

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locks your phone into 

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a vacuum seal to prevent 

distortion. Includes full answer, originate 

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duplex operation. Quality guaranteed as 

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leader in electronic marketing since 1975, 
now offers this introductory package of 
the Star Modem, adaptor and the 
CompuServe hookup, (order product 
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modem, adaptor and hookup, (order 
product #330), only $269.95. Optional 



10' cables are 
available for $24.95 
(order product #280). 
Quantities are limited so order 
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call our toll free number 24 hours a day 
or send your check but please allow time 
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Mastercharge or American Express 
cards are accepted. Add $5.00 for 
nsured postage and handling. California 
esidents add 6% sales tax. 



(800) 854-3831 



In California 
(800) 432-7451 



|"N\ A/C marketing 



1 international 



350-A Fischer Avenue, Depl. 99 

Costa Mesa, California 92626 

For dealer inquiries or product information call 

(714) 540-4549. & DW S marketing initriutioul 1980 



BYTE August 1980 221 



Buy By Mail 
and Save! 



COMPUTERS 




',. b&\ \« '■■ 



INTERTEC SuperBrain® 32K . $2495 

64K RAM, List $3345 $2695 

64K Quad, List $3995 $3395 

NORTH STAR Horizon I® 

16K D.D. Kit $1259 

32K D.D. Kit $1579 

32K Assembled, List $2695 .... $2149 

Horizon 2 32K DD, Assm., $3095 $2439 
32K QD, Assm., List $3595 .... $2859 




CROMEMCO Z-2, List $995 ... $ 829 

System 2, 64K, List $3990 $3179 

System 3, 64K, List $6990 $5479 

ATARI® 400, List $630 $ 489 

800, List $1080 $ 839 

TI-99/4, List $1150 $ 985 

DISK SYSTEMS 

THINKER TOYS® Discus 2D . $ 939 

Dual Discus 2D $1559 

Discus 2 + 2, List $1549 $1288 

PRINTERS & TERMINALS 
PAPER TIGER IDS-440 $ 849 

with Graphics Option $ 949 

CENTRONICS 730-1, List $995 . $ 639 

737, List $995 $ 849 

T.I. 810 $1575 

INTERTUBE II, List $995 $ 729 

PERKIN-ELMER Bantam 550 . . $ 789 

TELEVIDEO 912C $779 

920C $ 839 

HAZELTINE 1420 $ 839 

1500 $ 879 

SOROC 120 $ 745 

FLOPPY DISKS SPECIAL 

5%" Box of 10 ONLY $29.95 

(specify TRS-S0, North Star, SuperBrain, etc.) 

Most items in stock for immediate delivery. Factory sealed cartons, 
w/lull factory warranty. NYS residents add appropriate sales lax 
Prices do not include shipping. VISA and Master Charge add 3Y 
C.O.D. orders require 25% deposit. Prices subject to change without 
notice. 

Computers 
Wholesale 

P.O. Box 144 Camillus, NY 13031 
E (315)472-2582 



Listing 1: A test program for the 8085 microprocessor section of the video ter- 
minal. This should be programmed into the 2716 read-only memory. When the 
checkout terminal is connected using the temporary interface shown in figure 2 
and the 8085 is reset, this program should cause the ASCII character "U" to be 
printed continuously on the checkout terminal. 



0001 

oooo 
oooo 



OOOO 3E7B 

0002 [1301 

0004 3E27 

0006 D301 



i TEST PROGRAM I FOR rpl 

CNCTL FIJI I I 
ON IN fon 
CNOU1 FOU 

f IN it iai. ize i:t:" ;; i i 

i 

MUI A.07BH 

OUT CNCTI 

MUT A»027H 

dill CNCTL 

r 

i SFNn CONTINUOUS IJ'S FROM 8251 



0008 

OOOA 

00 oc 

00 OF 
0011 
0013 



riBoi 

E601 
CA0800 

3E55 
D300 

r: 30 boo 



.OOP 



IN 

ANT 

.17 

MOT 

OUT 

JMP 



CNCTI 

1 

I OOP 

A..055H 

CNOUT 

I OOP 



f 
SM 
rl 

; i 



np in a 

ASK IP 
OOP If 

OAfJ A 

FNlt OU 

OOP AN 



T ATI IS 
FAHY RT 
NUT lv I 
I FTTFP 
T FROM 
If SFNIi 



I 

AH i 
■II " 
8 2 SI 

NI-XT "1.1 



NO PROGRAM ERROR: 



8080 MACRO Ai3SFMBI.FR. OFR 2.0 FRRflRS 



PAGF 



SYMBOI 


TAHI F 










* 01 














A 0007 H 


oooo 


C 




oooi 


CNCTI 


000 1 


CNIN OOOO * CNOUT 


oooo 


li 




OOO':' 


F 


00 03 


H 0004 1 


0005 


1 OOP 




0008 


ii 


OOOA 


PSU 0006 SP 


0006 












CRT2B0 














100000003E7BD301 3E27ri 501 HBO 1 1 


cVO ICAO800 


«" 


-,'.' 






060010005SD300C30800F7 














oooooooooo 















100 
wv- 




CURRENT LOOP 
OUTPUT 



CURRENT LOOP 
INPUT 



Figure 2: Schematic diagram of the temporary interface for connecting the checkout 
terminal to the new terminal for debugging. 

Circle 165 on inquiry card. 



Circle 166 on inquiry card. 



779 upper CASE/lower case 
"Conversion Kit I" 

Expand the capabilities of your 779 line printer to 
include word processing!! Available to all Centronics 
779/TRS 80 Printer I owners is the option of lower 
case and changing slash zero to standard 0. No etch 
cuts or soldering needed, installs in minutes with a 
screwdriver. No program modification or additional 
interface is required. Price $125.00 

Motor control conversion kit ir 

FOR ALL CENTRONICS 779/TRS 80 PRINTER I UNE PRINTERS!! 

Our "Conversion Kit II" Motor Controller gives your 779 
the ability to turn the motor on and off automatically. 
Removes the annoying noise of constant run, 
increasing the life span of your 779 / TRS 80 line printer 
motor! No soldering, software or hardware changes 
needed. Installs easily. Price $95.00 

SAVE! Buy Service Technologies "Conversion Kit I" 
and "Conversion Kit II" together for the single price 
of $199.00 

To order, please send check or money order in the 
proper amount to: f . <7~ / / . d 

(Jervice ^Jechnoloaies, Jjnc. 

32 Nightingale Rd. 

Nashua, N.H. 03062 

(603) 883-5369 
Visa and Master Charge accepted (please include 
signature, expiration date and phone number) 

Service Technologies will pay all shipping and 
handling. 




ASI INTEGRATED BUSINESS 
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RECEIVABLES ORDER ENTRY 
PAYABLES INVENTORY 

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GENERAL LEDGER 

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PLUS TECHNICAL SUPPORT 
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Arkansas 
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8901 Kanis Rd. 
Suite 206 
Little Rock, AR 72205 
501) 227-8471 



Ng^ Produced and widely used in England and U.S.A. 
COMPLETE BUSINESS PACKAGE 

INCLUDES EVERYTHING FROM INVENTORY TO SALES SUMMARY 

PROMPTS USER, VALIDATES EACH ENTRY, MENU DRIVEN 

Approximately 60-100 entries/Inputs require only 2-4 hours weekly and your entire business is under control. 



PROGRAMS ARE INTEGRATED- 



SELECT FUNCTION BY NUMBER- 



01 = ENTER NAMES/ADDRESS, ETC 

02 = ENTER/PRINT INVOICES 
03= ENTER PURCHASES 
04 = ENTER A/C RECEIVABLES 
05= ENTER A/C PAYABLES 
06 = ENTER/UPDATE INVENTORY 
07= ENTER/UPDATE ORDERS 
08= ENTER/UPDATE BANKS 
09= EXAMINE/MONITOR SALES LEDGER 
10= EXAMINE/MONITOR PURCHASE LEDGER 

11 = EXAMINE/MONITOR (INCOMPLETE RECORDS) 

12 = EXAMINE PRODUCT SALES 



13 = PRINT CUSTOMER STATEMENTS 
14= PRINT SUPPLIER STATEMENTS 
15 = PRINT AGENT STATEMENTS 
16= PRINT TAX STATEMENTS 
17= PRINT WEEK/MONTH SALES 
18 = PRINT WEEK/MONTH PURCHASES 
19= PRINT YEAR AUDIT 

20 = PRINT PROFIT/LOSS ACCOUNT 

21 = UPDATE END MONTH FILES MAINTENANCE 
22= PRINT CASH FLOW FORECAST 
23= ENTER/UPDATE PAYROLL (NOT YET AVAILABLE) 
24 = RETURN TO BASIC 

WHICH ONE? (ENTER 1-24) 

01 SUB. MENU EXAMPLE: 01 = EXAMINE: 02 = INSERT: 03 = AMEND: 04 = DELETE 

05 = PRINT (1,2,3): 06 = NUMERIC COMBINATIONS: 07 = SORT 

VERY FLEXIBLE. ADD YOUR OWN FUNCTIONS. EASY TO INTEGRATE. 

All programs in BASIC for CP/M. PET. 6800 

G. W. COMPUTERS LTD, the producers of this beautiful package in U.K. 



WE EXPORT TO ALL COUNTRIES: 

BARCLAYCARD ACCEPTED 

CBM APPROVED 

CP/M Ver. 9.00 is one 16 K core program 

using random access releasing both drives for 

data storage, and 250 word vocabulary is 

translatable in any foreign language. 

PRICES: Programs 1-23 EXC (19,20,22,23) £475 



CALLERS BY APPOINTMENT ONLY 

89 Bedford Court Mansions 

Bedford Avenue 

London WC1, U.K. 



CONTACT TONY WINTER 01-636-8210 

BARCLAYCARD ACCEPTED 

CBM APPROVED 

CP/M Ver. 9.00 is one 16 K core program 

using random access releasing both drives for 

data storage, and 250 word vocabulary is 

translatable in any foreign language. 

£575 Stock Integrated Option + £100 Bank Integrated Option + £100 



Circle 168 on inquiry card. 



BYTE August 1980 223 







































8212 




8212 




24-PIN 

DIP PLUG TO 

KEYBOARD 






c 




RYSTAL . 






























\ 




8251 




74LS138 




8279 




1 




* 






















RESISTORS / 










2114 








a \ 

CAPACITORS \ 


















8257 




7401 




8- DIP 

SWITCHES 




8224 




2114 






























r 




7493 




7474 




2114 




8212 




8212 




















MCT 
-2 


MCT 
-2 




7490 




74LS138 




2114 










CRYSTAL 




















8085 




J 


7400 




7410 




74166 




74LS138 




































7400 




74S163 




74LS257 




2513 




2716 




















74175 




74175 




8131 
































8275 










74175 




74175 




74175 





































Figure 3: Diagram of the parts layout on the component side of the main circuit board of the video terminal. A type 4350 Vector wire- 
wrap board was used. 



mmxri 

371 FOB I»l TO K*N 

379iF«ix>a<i)Trar*i 

W*I>*CI> 
StlGCTI . 
4NOSUB7W 
411 IF F4 HO STOP 
*2» GOTO 138 
718 FOR M TO M 
711 F» J=l TO H 
721 Z*M)tt+j 

73i if kzm no mm* '. 

7¥i IF KZM THEN miMV r 

r» tea j 
79 nm 

TTiOKHJUiSm) 

m war* • *,c 

thoch 

mmm 



Photo 5: An example of the display pro- 
duced on the surplus Motorola video 
monitor. 



Text continued from page 220: 

pin 2 of the 8251. Check the TxC 
and RxC inputs of the 8251 (pins 9 
and 25). The frequency on these in- 
puts should be sixty-four times the 
desired data rate (ie: for 300 bps it 
should be 19,200 Hz). If this frequen- 
cy is not correct, check the connec- 
tions on the 7490 and 7493, as well as 
the data rate switch. The ALE line 
(pin 30 on the 8085) should have a 
frequency of about 650.8 kHz on it. 
There s hould be no activity on the 
ME MW li ne (pin 9 of the 74LS257). 
The IOR line (pin 7 of the 74LS257) 
should have a frequency of about 
92.2 kHz. The frequencies listed 
above should all be read with a fre- 
quency counter that uses a full 
1-second count period, since the 
pulses on many of these lines do not 
have a constant duty cycle. 
Erroneous readings can result from 
count periods shorter than one 



second. 

Until next month's BYTE arrives, 
you will have plenty of time to check 
the construction of this portion of the 
circuit. Then, in Part 2, we can pro- 
ceed with the rest of the project. ■ 



Portions of this article are copyright by 
Intel Corporation, and used by per- 
mission. 



What's going on 
where people 
worship today? 



Find yourself —with 
people who worship. 

A public service of WiT* 
this publication and Ihe Mfcyj 1 

Adverlising C&jncil. COLHC 




224 August 1980 © BYTE Publications Inc 



Circle 169 on inquiry card. 



Circle 170 on inquiry card. 



At last— NETWORKING! 






SATELLITE 



PRINTER 



HUB 



The CDL Network Operating System in your computers will 
give you: 

SA V I N GS One disk and printer can be shared among 
any number of satellite computers. Hard and floppy disk 
versions are available. 

POWER All satellites have a full CPM environment. 
You can access the largest collection of software available 
for microcomputers. 

FLEXIBILITY The network software can be adapted 
to your input/output hardware. It even adapts automa- 
tically to available RAM. 

The CDL Networking Operating System is a quality soft- 
ware product with excellent documentation backed by 
extensive testing. 

Write for information. 



CAMBRIDGE DEVELOPMENT LAB 

44 Brattle Street Cambridge, MA 021 38 



CATCH THE 

S-100INC. 
BUS! 



famObJWW 



LIST 
PRICE 



OUR 

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Tarbell Double Density Disk Controller 
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S.D. Systems SBC-100 Single Board 
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Godbout Econoram XIII - 16K - 
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Intertec "Super Brain" w/64K, 2 
Double Density Drives, CP/M etc. 

North Star Z-80A CPU - ZPB-A A&T 



495.00 399.00 

295.00 *252.00 

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3,345.00 2,675.00 

299.00 255.00 



'Included free with every S.D. Systems Board 
is an additional $25.00 manufacturers rebate coupon 

Subject to Available Quantities • Prices Quoted Include Cash Discounts. 
Shipping & Insurance Extra 

We carry all major lines such as 

S.D. Systems, Cromemco, Ithaca Intersystems, North Star, 

Sanyo, ECT, TEI, Godbout, Thinker Toys, Hazeltine, IMC 

For a special cash price, telephone us. 



Hours: 

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Address 7 White Place 

Clark, N.J. 07066 
Interface ....201-382-1318 



tki*< 



THE MAGAZINE FOR COMPUTER I STS 



AT LAST!! A MAGAZINE FOR LOVERS OF 

NEW PRODUCTS 

GAMES 

BUSINESS 

CLASSIFIED 

SCIENCE O 



• PERSONAL FINANCES & 
+++ANDMORE! 3? 

A DIVISION OF SAFETY-SWEET, INC, 



BASIC ! 

Advertisers: The first time you advertise 
in BASIC, it's free! Write for details 

YES, I LOVE BASIC™ 

— START MY SUBSCRIPTION WITH 
THE OCT. 1980 PREMIER ISSUE 

I ENCLOSE $20.00 FOR 12 ISSUES 

BASIC 



MAGAZINE 




P.O. BOX 42 SOUTH RIVER, NEW JERSEY 08882 



(Please Print) 



City/sute/Zip | may cance | m y subscription any time and receive a refund 
for the unused balance. 



Circle 171 on inquiry card. 



BYTE August 1980 225 



Clods and Newsletters 



Lifelines from Lifeboat 

The primary objective of 
Lifelines is to keep readers 
informed of the current 
status of all CP/M- 
compatible software. Issues 
include statistics on the wide 
variety of CP/M-compatible 
software products 
distributed by Lifeboat 
Associates. In addition there 
will be three sections dealing 
with changes, bugs, and 
new products. Letters from 
users are featured. The 
newsletter recently published 
a Pascal review and an arti- 
cle on undocumented Z80 
op codes. The subscription 
rate is $18 for twelve issues 
in the US, Canada and Mex- 
ico. Elsewhere the rate is 
$40. Write Lifelines, 1651 
Third Ave, New York NY 
10028. 



International Computer 

Chess Association Shifts 

Headquarters 

In order to handle the 
growing membership more 
effectively, the headquarters 
for the International Com- 
puter Chess Association 
(ICCA) has been transferred 
from Northwestern Univer- 
sity in Evanston, Illinois, to 
Bell Telephone Laboratories 
in Murray Hill, New Jersey. 
All inquiries and member- 
ship applications should be 
sent to ICCA, c/o of Ken 



Thompson, Rm 2C423, Bell 
Telephone Labs, Murray 
Hill NJ 07974. Editorial 
material for the newsletter 
should be sent to B Mitt- 
man, ICCA Newsletter, 
Vogelback Computing 
Center, Northwestern Uni- 
versity, Evanston IL 60201. 
Membership dues are $10. 
Back issues of the newsletter 
are $2 for a set of three. 



Another Club in Florida 

The Level II Club is an 
organization where TRS-80 
owners can exchange soft- 
ware. The group has a large 
program library and will 
soon offer an ads section 
and programming contests. 
There are no membership 
fees. For more information, 
write Level II Club, 3713 
Bay-to-Bay Blvd, Tampa FL 
33609. 



FORTH Interest Group 

The FORTH Interest 
Group meets on the fourth 
Saturday of each month in 
the Special Events Room of 
Liberty House Department 
Store, Southland Shopping 
Center, Highway 17 at Win- 
ton Ave, Hayward, Califor- 
nia. The group also 
publishes a newsletter, 
FORTH Dimensions. 
Editorial material is always 
welcome. A subscription to 



FORTH Dimensions is free 
when you join the FORTH 
Interest Group for $12 per 
year in the US, or $15 
overseas. Contact the group 
by writing, FORTH Interest 
Group, POB 1105, San 
Carlos CA 94070. 



International Apple Core 

The International Apple 
Core (IAC) is a nonprofit in- 
dependent organization that 
will act as the parent 
organization for local Apple 
computer groups. Member- 
ship is not open to in- 
dividuals, although they 
may subscribe to the IAC's 
quarterly publication. The 
organization will offer infor- 
mation on hardware, soft- 
ware, application notes, and 
programming tips to 
member groups. The IAC 
will also make its library ac- 
cessible to member groups. 
For more information, 
Apple user groups can con- 
tact the International Apple 
Core, POB 976, Daly City 
CA 94017. 



Free Pascal Newsletter 

The Pascal Newsletter has 
articles of general interest to 
computer enthusiasts, such 
as Pascal standards and pro- 
gramming techniques. Re- 
cent newsletter articles have 
included a history of Pascal 
compilers, a Pascal 



bibliography, a comparison 
of Rational Data Systems' 
(RDS) Pascal to competitive 
products, and a section on 
matters of programming 
style. Free subscriptions to 
RDS's Pascal Newsletter and 
a product brochure are 
available by writing or call- 
ing Rational Data Systems, 
245 W 55th St, New York 
NY 10019, (212) 757-0011. 



A Computer Group in 
Amarillo 

The High Plains TRS-80 
Users Group of Amarillo, 
Texas, meets the second and 
fourth Tuesdays of every 
month at the downtown 
branch of the Amarillo 
Public Library on 413 E 4th 
St, from 7 to 9 PM. The 
annual dues are $15. For in- 
formation, write High Plains 
TRS-80 Users Group, POB 
30545, Amarillo TX 79120. 



TBUG-80 in Florida 

This group in Tampa Bay, 
Florida, supports the use of 
the TRS-80 for games and 
business applications. 
Tutorial sessions at the 
meetings cover everything 
from the proper operation 
of the hardware to disk- 
based programming tech- 
niques. The club's newsletter 
contains program notes, 
reviews of products for the 
TRS-80, and letters of 



AIM 65 

AIM 65 is fully assembled, tested and warranted. With the addition of a low cost, readily available power 
supply, it's ready to start working for you. It has an addressing capability up to 65K bytes, and comes 
with a user-dedicated 1K or 4K RAM. 




• Thermal Printer 

• Full-Size Alphanumeric Keyboard 

• True Alphanumeric Display 

• Proven R6500 Microcomputer System Devices 



1 Built-in Expansion Capability 
i TTY and Audio Cassette Interlaces 
i ROM Resident Advanced Interactive Monitor 
Advanced Interactive Monitor Commands 



PRICE: $389.00 



Plus $4.00 UPS (shipped in U.S. must give street address), $10 parcel post to APO's, FPO's, Alaska, 
Hawaii.Canada, $25 air mail to all other countries 

We manufacture a complete line of high quality expansion boards. Use reader service card to be added 
to our mailing list, or U.S. residents send $1.00 (International send $3.00 U.S.) for airmail delivery of our 
complete catalog. 



PRICE: $139.00 

We also carry the SYM-1 
Microcomputer with manuals $229.00 



iTRNB>- 



ENTERPRISES 

INCORPORATED 



2967 W. Fairmount Avenue • Phoenix, AZ 85017 • (602) 265-7564 



226 August 1980 © BYTE Publications Inc 



Circle 172 on inquiry card. 



Circle 173 on inquiry card. 



Circle 174 on inquiry card. 



SOFTWARE 
WANTED 

If you are an 

inventive programmer 

and could use 

an extra income, 

please call: 

(213)894-9154 

We are interested in 
Games and Business software. 

Royalty or Gash-out basis. 

DATASOFT 

16606 Sehoenborn St. 
Sepulveda, Ca. 91343 



TOLL FREE ORDERING 




These Fine 
Products and More 




NORTHSTAR 

HRZ-1-32K-D 2100 

HRZ-2-32K-D 2400 

HRZ-2-32K-Q 2800 

HARDDISCSYSTEM 3950 

DYNA BYTE 

DB8/148K 2395 

DB8/2 48K 3900 

DB8/4 3030 

32M PHOENIX 11800 

TERMINALS 

TELEVIDE0912 775 

TELEVIDEO920 835 

SOROQ 10-120 740 

PRINTERS 

NEC5510 2700 

NEC5520 2975 

TI-820 1580 

ANADEX 795 

BASE2 600 

EPSON CALL 



THINKER TOYS 

DISCUS2 + 2 1265 

DISCUS 2D 980 

DISCUS M26 HARD DISC . . .4095 

SOLIDSTATEMUSIC Kit Assm 
SB1 SYNTHESIZER... .161 227 

VB1BVIDEO 125 170 

CB2Z80CPU 168 220 

MEASUREMENT SYSTEMS 

DM 3200 32K 250ns 500 

DM640064K250ns 640 

DMB3200 650 

SOFTWARE-DISCS— MISC 

CPM-2 150 

WORDSTAR 350 

GRAHAM-DORIAN CALL 

STRUCTUREDSYSTEMS . .CALL 

VERBATIM 5 (10) 28 

VERBATIM 8 (10) 35 

ATARI CALL 

TI99-4 CALL 



WE WILL TRY TO BEAT ANY ADVERTISED PRICE 

Automated Equipment Inc. 

4341 W. Commonwealth Ave Suite D 

Fullerton, Calif. 92633 

(71 4) 739-4701 (800) 854-6003 




*#5^q* 




A NEW CONCEPT IN APPLE ][• SOFTWARE 

Finally, a company specializing in software for the APPLE] tor] [ Plus and only APPLES! All your software 
shopping can now be done under ONE ROOF at TREMENDOUS SAVINGS! Because we sell software and 
only software, we receive discounts from ALL major Suppliers, such as: 

HAYDEN CREATIVE COMPUTING PERSONAL SOFTWARE 

PROGRAMMA MICROSOFT and MANY OTHERS 

and WE CAN PASS THESE SAVINGS ONTO YOU, the APPLE USER! 

If you are tired of page thumbing looking for APPLE programs, and want the best prices on ALL programs 
written for the APPLE, send for our FREE 40-page catalog and a $1 coupon good towards your first order or 
call us for our price on any APPLE program written and order by phone. M/C, VISA, BankAmericard ac- 
cepted. 

IF WE HAVEN'T GOT IT, IT HASN'T BEEN WRITTEN!! -Trademark of apple computers inc. 



Software Concepts 

948 Danvers Ave., Westerville, OH 43081 

(614)882-8007 



Hours: 

10AM-9PM Weekdays 
12Noon-5PM Saturdays 
Closed Sundays 



NEW PRODUCTS 



Lo-Res Graphics Pads 
Verbatim 5" Diskettes 
CASTLE ADVENTURE! 



$ 1.75/ea. 
$2.65/ea.(Quan 1) 
$17.95/disk 



Circle 175 on inquiry card. 



BYTE August 1980 227 



Circle 176 on inquiry card. 





COMPUTER 
FORMS KIT 

EACH KIT CONTAINS: 

Samples, Prices, Order Form, 

4 Checks, 2 Statements, 2 Invoices, 

Programming Guides. 

We specialize in small quantities, low prices. 
500 CHECKS ONLY $29.95 




SEND COUPON, CIRCLE BINGO or 
PHONE TOLL FREE 
1+800-225-9540 



FAST SERVICE - It Is our policy to ship within 6 working 
days following our receipt of your order. CODE 459 



Name. 



Address . 
City 



State, Zip 



NEW ENGLAND BUSINESS SERVICE, INC. 
GROTON, MASS. 01450 



general interest from 
members. For information 
on subscribing to the 
newsletter, joining the club, 
or learning about its elec- 
tronic mail system, write to 
the Tampa Bay TRS-80 
Users Group, T-BUG 80 
Newsletter, POB 247, 
Tampa FL 33602. 



Apple for the Teacher 

Apple for the Teacher is 
a user group with emphasis 
on the educational uses of 
the Apple computer. Its 
newsletter features reviews 
of educational software, plus 
current information on 
educational computer grants 
and research. The group 
operates the national 
computer-aided instruction 
library for the Apple and is 
receiving donations from 
throughout the world. Con- 
tact Apple for the Teacher, 
5848 Riddio St, Citrus 
Heights CA 95610. 



Computer Society in 
Washington 

The Whidbey Island Com- 
puter Society (WICS) is 
dedicated to promoting 
education and fellowship in 
the realm of home com- 
puting. The only require- 
ment for membership is an 
interest in the field of 
microcomputing. The group 
currently has an AIM-65, 
Apple II, Heathkit H8, 
TRS-80, Exidy Sorcerer, and 
a Z80 homebrew system. 
WICS meets monthly on the 
second and fourth Saturday. 
For further information, 
contact Dee Minter, 1616 
Larch Dr, Oak Harbor WA 
98277, (206) 675-7964. 



Gosub— TRS-80 Users 
Group 

Gosub TRS-80 Users 
Group was formed to pro- 
vide TRS-80 users with a 
place to exchange ideas, in- 
formation, and other 
computer-related material. 
The group meets on the 
third Sunday of each month 
in the computer room at the 
Camar Corporation, 186 



Prescott St, Worcester, 
Massachusetts. The meetings 
run from 2 to 5 PM. 
Membership dues are $6 per 
year and include a subscrip- 
tion to a monthly news- 
letter. The mailing address is 
POB 712, Worcester MA 
01613, (617) 845-1851. ■ 



BYTE's Bits 



First National 

Conference on Artificial 

Intelligence 

Stanford University in 
Palo Alto, California, is 
hosting the first annual Na- 
tional Conference on Ar- 
tificial Intelligence. The con- 
ference will be held from 
August 18 thru the 21. It is 
being sponsored by the new- 
ly created American 
Association for Artificial In- 
telligence (AAAI) in 
cooperation with SIGART. 
The topics will cover 
robotics, cognitive model- 
ing, vision, problem solving 
and search, artificial in- 
telligence languages and 
software, theorem proving, 
theoretical foundations, 
mathematical foundations, 
specialized systems, and 
more. Many artificial in- 
telligence research groups 
and manufacturers will be 
demonstrating AI and other 
computer hardware and 
software. A tutorial pro- 
gram on August 18 will ex- 
amine the current artificial 
intelligence research in this 
country. The AAAI is a 
group whose purpose is to 
study and disseminate infor- 
mation on AI in the US. 
AAAI officers are Allen 
Newell of Carnegie-Mellon 
University, president; Ed- 
ward Feigenbaum of Stan- 
ford University, president- 
elect; and Donald Walker of 
SRI-International, secretary- 
treasurer. Membership infor- 
mation may be obtained by 
writing to Dr Bruce 
Buchanan, AAAI Member- 
ship, Computer Science 
Dept, Stanford University, 
Stanford CA 94305. ■ 



228 Augusl 1980 © BYTE Publications Inc 



Circle 178 on inquiry card. 



CHECKERS 



Our program can solve the difficult 
endgame problem on the right (solution 
22-18, 9-13, 18-15, 13-17, 11-16, 3-8, 16-12, 
8-3, 15-11, 17-22,12-16). 

It also has 
. mam Vines for most of the ACF 3- 

move openings in its book 
. special coding for 2 kings vs 1 and 3 
vs 2 with defenders in the double 
corners 
. the ability to take back moves 
. the ability to set up board positions 
. recent moves displayed along with 
text or graphics representation of 
board position 
. 9 levels of play 

. the ability to run in 16K RAM on a Z-80 
. a $24.95 price tag 

Gomoku 

Our Gomoku program was the highest 
ranking program in the 1980 North 
American tournament. It has two levels 
of play, and is available with 19 by 19 
(except TRS-80) or 16 by 16 (except 
CP/M) board. It was written by the 75, 77, 
79 North American champion, requires 
32K RAM (for N'DOS must begin at loc. 
zero), and costs $29.95. 



Guess Five 

This number guessing program uses 
five digits, each valued thru 7 making 
32768 possible numbers. When the pro- 
gram is guessing it typically makes four 
guesses from book, one by short calcula- 
tion and hits on the sixth guess. You 
have to try this to believe how high that 
standard is. It requires 8K RAM and 
costs$19.95. 



1 

SB 

»] 

1 * 


e 


2 ■ 

ioH 


3~M 4~1 
1lH 1 12 [ 


1 ,3 H 


14 


1 15 


1S H 


17 




18H 


<"■ 1 20| 


Z1 H 


22 


r 23 


i ^<iflfl 


2B 

^29^B 


30 


29 H 

^31 


27«H ^"1 
^32^B 



While la win. Dr. T. Brown 1671 

All programs 

... are available for TRS-80 (delivered 
on level II tape), North Star DOS 
(delivered on 5" North Star diskettes 
which need N* drives to read them), and 
CP/M (on 5" N" or 8" single density IBM 
format disk). Visa or Mastercharge 
accepted. Please add 5 dollars extra for 
8" disk. Ontario residents add 7% tax, 
Canadian residents^add 9% tax. Order 
from 



VfVv 

tware, Q 



Five Stones Soft 
P.O. Box 1369. 
Station B, 
OttawaK1P5R4 
Canada 



CP/ M is a trademark of Digital Research. 
TRS-80 is a trademark of Tandy Corp. 



GIVE 

YOUR 

COMPUTER 

A 

HAND 




Have you ever wanted to do more with your micro than play computer 
games and balance your checkbook? Robotics Age gives you all the 
information you need to transform your home computer into a working 
ROBOT! Every aspect of robot research and experimentation— from 
the basic principles to the latest developments in laboratories around 
the world— is covered. Special emphasis is given to plans, circuits, and 
programs that you can use in your own microcomputer-controlled 
robot. Each article is designed to be understandable to the novice 
experimenter, but with technical detail and complete references that 
will satisfy even the professional researcher. Added to that are 
robotics-related New Products, Book Reviews, abstracts of selected 
recent technical papers, and reports on how you can participate in the 
growing number of robotics and Artificial Intelligence organizations in 
the US and abroad. Join the thousands of Robotics Age readers and 
learn how you can contribute to the development of the intelligent 
robots of the future— Subscribe Today! 



R030UIOage 


P.O. Box 801 


La Canada. CA 91011 




D 1 yr (4 issues)— US;$8 50 
D 2 yrs. (8 issues)— US:$16, 
Paymeni unclosed d Bill me 


Canada & Mexico:SlO 
Canada & Mexico: 519 
(Nn America only)D Bi 


Foreign S1 2 
Foreign:$23 
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Number * 


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=xptralion dale ! 




r..t y 













CP/M® 1 - based Business Software for TRS-80® 2 computers on 
. . . the fastest Mod-ll CP/M with the most features!!! 



• Over 610,000 bytes/disk 

• Downloading package included 

• 1,200 baud operation of serial 

printers without data loss 

• Single drive backup 



• Mixed single/double density on any 

of 4 drives (even a 1 -drive system) 

• Ultra-fast disk operation 

• Emulation of cursor addressing for 

any of several "dumb" CRTs 



Auto-LF printer support & ASCII 
top-of-form software (LPIII) 

Supplemental document describing 
our implementation 

User-settable function keys 



MOD-II CP/M $250.00 MOD-I CP/M $150.00 CBASIC2® 3 (Mod I or II) $110.00 

The following software for Mod-ll CP/M only unless otherwise stated (*-requires CBASIC2): 

MAGIC WAND® 5 - Full-feature word processing, true proportional 
spacing, file merging, and use of full-screen editor for source 

programs or data $400.00 

RPA (Residential Property Analysis) -Analyzes income and expense, 
financing, taxes, inflation and depreciation on home, condo, or 
apartments over a user.-selectable time. Shows payoff in terms of 
ROI, Cap rate, cash-on-cash. Amortization schedules and 
worksheet $300.00* 

demo disk & manual 35.00* 

RBC (Rent/Buy Comparison) - Sales or investment tool to compare 
renting and savings account investment vs. purchasing a particular 
property $250.00* 

demo disk & manual 35.00* 



RM/COBOL" 4 - Only COBOL for CP/M with alternate keys (multi- 
key ISAM), CRT screen handling, interactive debug, Z80 code, and 
the most useful Level 2 features. Compatible with Tandy's 

COBOL-but runs faster! $495.00 

PMS (Property Management System) - Interactive, menu-driven 
system includes full G/L, budgeting, cash journal, delinquency 
list, tenant activity/rent roll, complete audit trail and reports 

on vacancies, lost rent, and vendors $650.00* 

demo disk & manual 75.00* 

APH (Automated Patient History) - General-purpose question- 
asking, answer-printing system furnished as self-administered 
review-of-systems general patient history (Mod-I also) . . . $1 75.00* 

Osborne & Assoc. CBASIC source programs (Mod-I also): 

Payroll w/Cost Accounting $250.00* General Ledger w/Cash Journal $250.00* 

Accts. Payable/ Accts. Receivable $250.00* O&A CBASIC Books (ea.) $ 20.00 

\ferbatim® 6 media: (Qty. 100 prices) 

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s4 Ryan-McFarland Corp. 

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o6 Verbatim Corp. 



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TEL: (0734) 470425 



BYTE August 1980 229 



Circle 179 on inquiry card. 



M7 Communicator 

A complete A/D and D/A 
Control System - 

Interface your computer to the analog 
world of process monitoring trans- 
ducers and controlling actuators. 





The M7 multiplexes analog and digital signals from your 
process sensors -temperature, pressure, level, flow, mass, 
strain, etc. -and continuously down-loads this data in digital 
form to your computer for display and processing. Simulta- 
neously, command signals are transmitted to the control 
devices in your process. 

Order a complete basic M7 
System ready for round-the- 
clock process control- 

including a 16/32-Channel A/D Input Module (expandable 
to 256 channels), a Computer Interface Module, and a 
4-Channel (expandable) D/A Output Module. Supplied com- 
plete with cabinet, power supply, and all necessary hardware 
and software for basic control. Bus accommodates eight 
additional modules. Specify computer make 
and model when 
ordering . . . each $2,990 

Or, 

order individual 

IEEES-100 

building block modules 

Supplied complete with fundamental control software: 
A/D Module, AIM-1 2 

• 1 6/32 channel • 1 2-bit precision/accuracy • 30 kHz data 
rates • 1 - 1 000 gain amplifier optional from $575 

Thermocouple Compensation Module, THM-8 

• 16 Inputs $350 

Signal Conditioners, SIG-1 • Long-line drive $325 

Additional Support Programs, PROG A,B,C. . . 

• Signal averaging • control functions • special display • 
etc from $1 00 

D/A Module, AOM-12 

• 4-channel (expandable) • 12-bit precision/ 
accuracy • Output: selectable voltage ranges and 
oscilloscope from $495 

Control Output-Current Module, VIC 4-20 

• 4-20 mA standard industrial control output • 12-bit pre- 
cision/accuracy • 4-channel • Use with AOM-1 2 .... $395 

Programmable Clock/Calendar Module, CLK-24 

• Minimum 1 year back-up $250 

Parallel Output Module, REL-8 

• 8-channel on-off (bang-bang) control $325 

Add-On Nonvolatile Memory Modules 

• 4K and 8K bytes from $320 



DUAL SYSTEMS CONTROL CORP. 
1825EastshoreHwy. 
Berkeley, CA 94710 
(415)549-3854 



system reliability/system integrity 




Event Cueise 



AUGUST 1980 



August 4-6 

Data-Entry Management and 
Supervision Seminar, 

Chicago IL. This seminar is 
designed for data-entry 
managers and supervisors. 
Topics will range from data- 
entry control techniques and 
improving data-entry 
operator productivity, to 
personnel communications 
and motivation. Contact 
MIC, 140 Barclay Ctr, 
Cherry Hill NJ 08034, (609) 
428-1020. 

August 12-14 

Computer Graphics '80, 
Birmingham, England. Com- 
puter Graphics '80 will bring 
together experienced users 
and specialists to present ap- 
plications experiences and 
research findings. In 
addition to the conference, 
there will be an equipment 
exhibition and an animated 
film festival. To register, 
contact Paula Stockham, 
Online, Cleveland Rd, 
Uxbridge UB8 2DD, 
England, phone Uxbridge 
(0895) 39262. 

August 14-24 

Electronics/China '80, 

Guangzhou (Canton), 
China. This is the first 
exhibition of US electronic 
companies in the People's 
Republic of China. The 
United States-China Trade 
Consultants are the sponsors 
of the show. Products 
demonstrated will include 
circuit components, system 
elements, test instrumenta- 
tion, product equipment, 
and materials. Details are 
available through Expo- 
consul Inc, Clapp and 
Poliak Inc, Princeton- 
Windsor Office Park, POB 
277, Princeton Junction NJ 
08550. 

August 23-24 

Personal Computer Arts 
Festival, Philadelphia Civic 
Center, Philadelphia PA. 



Tutorials, seminars, musical 
performances, and graphic 
extravaganzas will be 
featured in this show. 
Contact PCAF '80, c/o 
Philadelphia Area Computer 
Society, POB 1954, 
Philadelphia PA 19105. 

August 18-21 
First National Conference on 
Artificial Intelligence, Stan- 
ford University, Palo Alto 
CA. This is the first annual 
National Conference on Ar- 
tificial Intelligence. It is be- 
ing sponsored by the newly 
created American Associa- 
tion for Artificial In- 
telligence in cooperation 
with SIGART. The topics 
will cover robotics, 
cognitive modeling, vision, 
problem solving and search, 
artificial intelligence 
languages and software, 
theorem proving, theoretical 
foundations, mathematical 
foundations, specialized 
systems, and more. Many 
artificial intelligence research 
groups and manufacturers 
will be demonstrating AI 
and other computer hard- 
ware and software. A 
tutorial program on August 
18 will examine the current 
artificial intelligence research 
in this country. Information 
may be obtained by writing 
to Dr Bruce Buchanan, 
AAAI Membership, Com- 
puter Science Dept, Stanford 
University, Stanford CA 
94305. 



Angus! 25-27 

Summer Computer Simula- 
tion Conference, Olympic 
Hotel, Seattle WA. 
Emphasis will be on com- 
puter networks, graphics 
tools for simulation, data- 
base management, and 
management science models, 
in addition to papers in such 
traditional areas as simula- 
tion. For details, write 
Simulation Councils Inc, 
1980 Summer Computer 
Simulation Conference, POB 
2228, La Jolla CA 92038. 



230 August 1980 © BYTE Publications Inc 



Circle 180 on inquiry card. 



August 25-28 
Implementing Cryptography 
in Data Processing and 
Communications Systems, 

University of Southern 
California, Los Angeles CA. 
For information on this con- 
ference, contact the Univer- 
sity of Southern California, 
Continuing Engineering 
Education, Powell Hall 216, 
University Park, Los 
Angeles CA 90007, (213) 
746-6708. 

A ugust-December 
Short Courses, George 
Washington University, 
Washington DC. These 
courses will cover program- 
ming for beginners, con- 
figuration management of 
software programs, com- 
puter performance evalua- 
tion, Pascal programming, 
and more. Contact the 
Director, Continuing 
Engineering Education Pro- 
gram, George Wasington 
University, Washington DC 
20052, (202) 676-6106, or 
toll-free (800) 424-9773. 



August-December 
Information Management 
Seminars for Professional 
Development, Harvard 
University, Cambridge MA. 
Courses on data com- 
munications, distributed 
systems, office automation, 
minicomputers, data-base 
management, computer 
graphics, computer map- 
ping, and more, are being 
presented by the Laboratory 
for Computer Graphics. 
Write the Center for 
Management Research, 850 
Boylston St, Chestnut Hill 
MA 02167, (617) 738-5020. 



SEPTEMBER 1980 

September 9-10 

The Thirteenth International 
Symposium and Exhibition 
on Minicomputer and 
Microcomputer Applica- 
tions, MIMI'80, Montreal, 
Canada. This symposium 
will cover communications, 
signal processing, data ac- 
quisition, control, robotics, 
education, hardware, 
languages, networks, and 
other topics. It is being held 
in conjunction with the first 



IASTED International Sym- 
posium and Exhibition on 
Office Automation. For 
more information, contact 
Professor M H Hamza, Dept 
of Electrical Engineering, 
University of Calgary, 
Calgary, Alberta, I2N 1N4 
Canada. 

September 11-13 
Internepcon Semiconductor 
International Exposition and 
Conference, Republic of 
Singapore. Featuring an ex- 
hibition of production 
machinery, tools, hardware, 
materials, and test 
instruments, this show 
includes conferences keyed 
to the needs of the engineer- 
ing, manufacturing, and 
support personnel of 
Southeast Asia. It is open to 
all persons engaged in elec- 
tronics and semiconductor 
manufacturing. Contact 
Industrial and Scientific 
Conference Management 
Inc, 222 W Adams St, 
Chicago IL 60606, 
(312) 263-4866. 

September 16-18 

Wescon/80, Anaheim 
Convention Center, 
Anaheim CA. This year's 
show will include a large 
exhibition and a variety of 
talks covering communica- 
tions, computers, micro- 
processors, consumer elec- 
tronics, energy, office 
automation, semiconductor 
technology, and more. 
Contact Wescon, 999 N 
Sepulveda Blvd, El Segundo 
CA 90245, (213) 772-2965. 

September 16 thru October 16 
Eastern European Electronics 
Catalog Exhibit. Exhibits 
will focus on production 
tools and machines, test in- 
strumentation, electronic 
components and hardware, 
computers for production, 
chemicals, and other 
materials. Symposia will 
cover electronic manufactur- 
ing techniques and pro- 
gressive production com- 
puter technology. The host 
cities will be: Warsaw, 
Poland; Bucharest, 
Rumania; Sofia, Bulgaria; 
Budapest, Hungary; and 
Prague, Czechoslovakia. 

For more information con- 
cerning the dates of ap- 



Fifty Years 
Innovation 




Ca**** t £ s and 
■" B ° b ?ter Vision 
tenri s 



Immediate Dallas 
Openings 

Texas Instruments has immediate 
openings for highly motivated, talented 
individuals with interest in the areas of 
robotics and pattern recognition. You 
will be a member of a team whose 
function is to develop and apply 
advanced technologies, design and 
implement working systems, and 
develop state-of-the-art tools and 
procedures for a broad range of 
industrial automation applications. 

We have positions for innovative 
individuals with background in: 

Hardware/Software 

Computer Architecture 
Operating Systems 
Systems Programming 
Mini/Micro Assembly Language 

Programming 
Electro Optics 
Video Signal Processing 

Applications 

Robotics 

Computer Vision System 

Computer Speech I/O 

Intelligent Machines 

Advanced Servo Control Systems 

Vidicon/CCD Cameras 

If you have an Associate or higher 
degree, or equivalent experience, and 
are looking for a challenging 
opportunity in any of the above areas, 
send your resume in complete 
confidence to: Staffing Manager/P.O. 
Box 225474, M.S. 217/Dallas, TX 75265. 

Texas Instruments 

INCORPORATED 

An equal opportunity employer M/K 



August 1980 © BYTE Publications Inc 231 



More Printing Terminals 
From MICROMAIL . . . 




DIABLO 1650 



• Prints at 40 cps, using 88, 92, or 
96 char, metalized printwheels. 

• Vertical resolution 1/48"; Horizontal 
1/120". Capable of proportional 
spacing, bidirectional printing, and 
graphics under software control. 

• Bidirectional normal and direct tabs. 
Left, right, top and bottom margins. 

R.O. $2890.00 
KSR $3285.00 



DIABLO 1640 

• Uses plastic printwheel and prints at 
45 cps. Otherwise, shares identical 
features with 1650 including: 

— Friction or tractor feed, up to 
15" wide. 

— Cartridge ribbon, fabric or carbon. 



(Shown with optional forms tractor and numeric 
keypad). 

• Prints 10, 12, 13.2, or 16.5 
characters per inch, upper/lower 



• Friction feed, paper width to 15 

$999.00 

Options: 

— Numeric keypad — $80.00 

— Adjustable forms tractor — 
$130.00 



R.O. $2745.00 
KSR $3140.00 




• Includes upper/lower case option'. 

• Bidirectional printing at 1 50 cps. 

• Tractor-feed forms, 3" to 1 5" 
wide. 

$1599.00 

Options: 

— Forms length control —$100.00 

— Vertical Format Control with 
Compressed Print — $125.00 



Prints 1 32 columns, upper/lower 
case with true descenders. 

30 character/second print speed. 
110-300 baud. 

Uses 12" wide by 8.5" pinfeed 
paper. 

Print position scale, paper guide 
and supply rack. 

$999.00 



We Also Represent the Following Manufacturers: 
SOROC TEC GTC 

Write or Call In for Our Free Catalogue! 



cMJCRDIYIflJL, 



MICROMAIL • BOX 3297 • SANTA ANA, CA 92703 
(714) 731-4338 



TO ORDER: Send check or money order to: MICROMAIL, P.O. Box 3297, Santa 
Ana, CA 92703. Personal or company checks require two weeks to clear. Termi- 
nals in stock are shipped the business day after receipt of certified funds. All 
equipment includes factory warranty. 

SHIPPING: We ship freight collect by UPS when possible. Larger terminals are 
shipped by motor freight. Air and express delivery is available on all products. 



pearance in each city and 
any other information, con- 
tact Harry Lepinske, East- 
West Operations, ISCM Inc, 
222 W Adams St, Chicago 
IL 60606. 

September 17-19 

ACM Small/Personal Com- 
puter Conference, Rickey's 
Hyatt House, Palo Alto CA. 
This symposium will blend 
contributed papers with 
panel and informal discus- 
sions. Included will be hard- 
ware and software topics in- 
volving theory, design, con- 
struction, marketing, and 
applications. Discussions 
will cover microcomputer 
applications in business, 
industry, education, and the 
home. Details are available 
from Conference Chairman, 
Philippe Lehot, PLA, 976 
Longridge Rd, Oakland CA 
94610. 

September 18-21 
Mid-Atlantic Business and 
Home-Computer Show, DC 

Armory /Starplex, 
Washington DC. This is an 
end-user exposition featuring 
small- and medium-sized 
business systems, scientific 
and engineering computers, 
microcomputers, and elec- 
trotechnology. Contact 
Northeast Expositions Inc, 
POB 678, Brookline Village 
MA 02147, (617) 524-0000. 

September 22-25 

Software INFO, Hyatt 
Regency, Chicago IL. This is 
the first national conference 
and exhibition on packaged 
software held in the US. For 
more information, or to 
reserve exhibition space, call 
or write Software INFO, 
Suite 545, 222 W Adams St, 
Chicago IL 60606, (312) 
263-3131. 

September 23-25 

Compcon '80 Fall, Capital 
Hilton Hotel, Washington 
DC. Sponsored by the 
Institute of Electrical and 
Electronics Engineers (IEEE), 
this show explores 
distributed computing and 
related topics. Discussions 
will cover interfaces, stan- 
dards, and protocols; data 
communications and net- 
working; computer systems; 
data bases; security; office 

Circle 181 on inquiry card. 



systems; and more. Details 
from Compcon '80 Fall, 
POB 639, Silver Spring MD 
20901. 

September 24-27 

The Tenth Annual Con- 
ference of the Society for 
Computer Medicine, San 
Diego Hilton, San Diego 
CA. This conference has 
been planned for physicians, 
attorneys, administrators, 
computer professionals, 
comptrollers, engineers, 
nurses, and anyone in- 
terested in the use of com- 
puters for patient care. Ses- 
sions on medical subjects, 
technical subjects, and con- 
tributed papers on new 
research in computer 
medicine will be offered. For 
information, contact Society 
for Computer Medicine, 
1901 N Ft Myer Dr, Suite 
602, Arlington VA 22209, 
(703) 525-0098. 

September 25-28 

Mid-Atlantic Personal and 
Business Computer Show, 

Philadelphia Civic Center, 
Philadelphia PA. General 
admission for adults is $5. 
This show is being produced 
by National Computer 
Shows, POB 678, Brookline 
Village MA 02147, (617) 
524-0000. 

September 26-27 
Classroom Applications of 
Computers in Grades K 
Thru 12, Independence High 
School, San Jose CA. A 
visit to "Silicon Valley," 
tutorials, workshops, and 
exhibits will highlight this 
conference. The emphasis 
will be to inform teachers 
about the possible uses of 
computers in all areas of 
education. Contact 
Computer-Using Educators, 
c/o W Don McKell, 
Independence High School, 
1776 Educational Park Dr, 
San Jose CA 95133. 

September 27-28 
New Jersey Personal Com- 
puter Show and Flea Market 
—80, Holiday Inn (North) 
Convention Center, Newark 
NJ. This show will feature 
an indoor commercial 
exhibit and sales area, an 
outdoor flea market with 
room for 100 sellers, and 



Circle 182 on inquiry card. 



forums for all popular 
hobby computing systems. 
This show is primarily for 
hobbyists and small-business 
owners. The admission price 
is $4 in advance and $5 at 
the door. Contact NJPCS, 
Kengore Corporation, 9 
James Ave, Kendall Park NJ 
08824, (201) 297-6918 after 7 
PM. 

September 29-October 4 
The Eighth International 
Conference on Computa- 
tional Linguistics, Tokyo, 
Japan. This conference will 
provide a forum for a 
variety of computational 
linguistics topics including 
theories, methods, and 
problems of computational 
linguistics; models of natural 
language processing; ap- 
plications of natural 
language processing; hard- 
ware and software supports 
for language data process- 
ing; and more. For informa- 
tion, contact Professor 
David G Hays, Twin 
Willows, 5048 Lakeshore 
Rd, Hamburg NY 14075. 



OCTOBER 1980 

October 6-8 

APL Users Meeting. Toron- 
to, Canada. This conference 
is aimed at APL users as 
well as those considering the 
future use of APL in their 
systems. Speakers will pre- 
sent papers that discuss the 
practical use of APL, 
managing APL resources, 
teaching APL, and APL pro- 
gramming techniques will be 
covered. The registration fee 
of $180 (Canadian currency) 
includes a copy of the pro- 
ceedings. For a brochure and 
registration material, contact 
Rosanne Wild, I P Sharp 
Associates Ltd, 145 King St 
W, Toronto Ontario M5H 
1J8, Canada. 

October 6-9 and 14-17 

The Eighth World Computer 
Congress, Tokyo, Japan, 
and Melbourne, Australia. 
Computer architecture and 
hardware, software, data 
base and information 
systems, computer networks 
and communication, infor- 
mation processing and 
education, and computers in 



everyday life are some of 
the topics that will be 
discussed at this conference. 
There will also be a large ex- 
hibition of hardware and 
software at the conferences. 
Contact the US Commit- 
tee for IFIP Congress '80, 
c/o The Bowery Savings 
Bank, 110 E 42nd St, New 
York NY 10017. 

October 8-10 

Circulation Computer 
Systems Symposium, 

Chicago Marriott Hotel, 
Chicago IL. More than 425 
newspaper publishers, 
general managers, circula- 
tion directors, controllers, 
and data-processing 
managers are expected to at- 
tend. Workshop sessions 
will be held for participants 
who already have or who 
are considering automated 
circulation systems. For 
more information, contact 
American Newspaper 
Publishers Association, The 
Newspaper Center, POB 
17407, Dulles Airport, 
Washington DC 20041, (703) 
620-9500. 



October 26-29 
International Data 
Processing Conference and 
Business Exposition, 

Philadelphia Sheraton Hotel, 
Philadelphia PA. This con- 
ference is being sponsored 
by the Data Processsing 
Management Association. 
Contact Conference Coor- 
dinator, DPMA Interna- 
tional Headquarters, 505 
Busse Hwy, Park Ridge IL 
60068, (312) 825-8124. ■ 



In order to gain optimal 
coverage of your organi- 
zation's computer con- 
ferences, seminars, work- 
shops, courses, etc, notice 
should reach our office at 
least three months in advance 
of the date of the event. 
Entries should be sent to: 
Event Queue, BYTE Publica- 
tions, 70 Main St, Peter- 
borough NH 03458. Each 
month we publish the current 
contents of the queue for the 
month of the cover date and 
the two following calendar 
months. Thus a given event 
may appear as many as three 
times in this section if it is 
sent to us far enough in 
advance. 



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check or M.O. Please include phone number. Personal or Co. 
checks require two weeks to clear. Items in stock will be shipped 
next business day upon receipt of certified funds. Within Calif, 
add 6% sales tax. All prices and offers subject to change without 
notice. Factory warranty included. 

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August 1980 © BYTE Publications Inc 233 



Circle 183 on inquiry card. 

MwY° u can talk to mor e 
f 'computers, faster and easier, 
with the 

VET/2 f™™ SCOTT 




The Scott VET/2 is a compact, highly versatile Voice 
Entry Terminal developed for TRS-80 users — and 
available soon for the PET and APPLE computers. Key 
features of the VET/2 include: 

• Easy to use — all programs may be written in Level II 
BASIC. One USRn statement is all that's needed to 
allow your program to be voice controlled. 

• Performance comparable to systems costing $10,000 
or more. 

• High accuracy (98+%) and fast recognition. 

• Supplied with demo programs and software tools. 

• Connects directly to screen printer I/O port. 

• Simplified training mode with automatic prompting. 

• Overlay features make vocabulary size virtually 
unlimited. 

The user manual fully describes the operation and 
training procedures for the VET/2 and includes com- 
plete instructions on interfacing the VET with BASIC 
programs. 

All hardware covered by 90-day warranty. Software 

guaranteed for replacement only. Prices subject to change 

without notice. 

Send coupon or telephone today for more information! 



815 North Elm 
INSTRUMENTS Denton, Texas 76201 

Please place my order for: 
D VET/2 (includes manual 

and shipping $898.50 

□ VET/2 Operator's Manual $7.20 

Texas residents add 5% tax 

California residents add 6% tax 

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Ship to: _ 
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Sig. . 



Ask BYTE 



Conducted by Steve Ciarcia 



In "Ask BYTE," Steve Ciarcia answers questions on any 
area of microcomputing. The most representative questions 
received each month will be answered and published. Do 
you have a nagging problem? Send your inquiry to: 

Ask BYTE 

c/o Steve Ciarcia 

POB 582 

Glastonbury CT 06033 
If you are a subscriber to The Source, send your questions 
by electronic mail or chat with Steve (TCE317) directly. Due 
to the high volume of inquiries, personal replies cannot be 
given. Be sure to include "Ask BYTE" in the address. 



-All orders must be signed. ^ 



Liquid-Crystal Displays 

Dear Steve, 

I recently examined a 
Milton Bradley Microvision 
miniature video game, 
which features a 1.5-inch- 
square liquid-crystal display 
(LCD) consisting of 16 rows 
of 16 square blocks. I want 
to build a circuit to drive 
this display unit. How dif- 
ficult would it be to modify 
the circuit you presented for 
use with an 8-by-16 array of 
light-emitting diodes (LEDs)? 
(See "Self -Refreshing LED 
Graphics Display," by Steve 
Ciarcia, October 1979 
BYTE, pages 58 thru 69.) 
The LCD display unit could 
provide useful capability to 
a single-board microcom- 
puter. 

I have also considered 
developing a programmable 
game cartridge for the 
Microvision console. The 
console contains two 9 V 
battery cells, a voltage 
regulator, a potentiometer 
"paddle control," a 
piezoelectric beeper, a 
4-by-3 printed-circuit 
keypad, the LCD unit, and 
a 40-pin dual-inline-package 
integrated circuit that ap- 
pears to be the display 
driver. The Blockbuster 
game cartridge that comes 
with the console contains a 
28-pin integrated circuit, a 
window for the display, and 
labeled cutouts for four 
control keys, along with 
passive components. Com- 



munication between the car- 
tridge and the console is via 
a 24-pin connector. 

I don't expect you to 
design circuits for me; if you 
did that for everyone who 
writes, you would not have 
enough time for your own 
work. However, you could 
do me a real favor by identi- 
fying two integrated circuits 
in the Microvision game. 
The first has 40 pins and is 
marked "SCUS0488, H 
7920." The second has 28 
pins and is marked 
"TMS1100NLL, MP 3450A, 
DBU7932." 

I hope you will keep up 
the good work. 
Daniel Q Dye Jr 

A lot of people are in- 
terested in using the LCD 
unit you mention. However, 
LEDs (light-emitting diodes) 
and LCDs have very dif- 
ferent principles of opera- 
tion. An LED becomes a 
source of light when you 
pass an electric current 
through it, consuming a fair 
amount of power. LCDs, on 
the other hand, act as 
voltage-controlled reflectors 
of light. When an AC 
voltage (not DC) is applied 
to a liquid-crystal display, 
the liquid changes from 
transparent to opaque, con- 
suming relatively little 
power. Because of this, the 
design approach in my LED 
project does not work for 
LCDs. But don't despair: 1 

Continued on page 238 



234 August 1980 © BYTE Publications Inc 



Circle 184 on inquiry card. 



Circle 185 on inquiry card. 




yOU DIDNT KNOW! 



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• Programs 2 PROMS for less 
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• Connect 2 or more in paral- 
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I becomes disk compatible with the Model II. 



Standard features include lowercase support, 
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FIELD PROVEN DESIGNS- After one year of 
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See reviews in July 80 and August 80 BYTE By Jerry Pournelle. 




•CIVM is a TM of Digital Research. TKS-80 is a TM of Tandy Corporation. 



Circle 186 on inauirv card 





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TRS-80 



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by Phelps Gales 

The powerful scientific language is now 
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book separately $15.50 + $1 

UP PERISCOPE 

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Two players are pitted against one 
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Your favorite arcade is now available for 
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APPLE* 

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The original of ADVENTURE written for 
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32K disk machine language $29.95 

ANDROID NIM 

by Leo Christopherson 
The game that made Leo Christopherson 
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The improved graphics and color of the 
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MAGIC PAINT 8RUSH 

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You don't have to be an engineer or 
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ATARI 



PET 



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High quality graphics program for the 
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STARFLEET ORION 

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RESCUE AT RIGEL 

Search the moon base and rescue Delilah 

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TIME TREK 

by Brad Templeton from Personal 
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To order: Call Toil-Free 1-800-258-1790 on nh can (mwsw) 

The Software Exchange & HardSide (Div. of Robitaille & Sons. Enterprises. Inc.;, SoftSide Publications 



236 BYTE August 1980 



Circle 187 on inquiry card. 



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Circle 188 on inquiry card. 



BYTE Augusl 1980 237 



Continued from page 234: 
have written a tutorial arti- 
cle on LCDs to be presented 
in the October Ciarcia's 
Circuit Cellar. 

Concerning the com- 
ponents in the Microvision: 
the 28-pin device is a Texas 
Instruments TMSlOOO-series 
4-bit microprocessor, that 
uses CMOS (complementary 
metal-oxide semiconductor) 
technology . The program 
for the Blockbuster game (or 
other game) is contained 
within it in a read-only 
memory. The 40-pin part is 
a custom multiplexed 
display-driver circuit for the 
LCD unit. The display 
driver is driven through the 
I/O (input/output) lines of 
the microprocessor. 1 hope 
I've helped. 
Steve 



The Very Busy Box 

Dear Steve, 

In all of your articles 
(which I read avidly) I have 
not seen any projects 
directed towards the Heath 
H8 computer system. I con- 
structed my H8 hoping to 
learn about computer hard- 
ware, but instead found 
myself only following in- 
structions. I find it very dif- 
ficult to apply your projects 
to my system. It would be 
of great benefit if, in one of 
your articles, you would in- 
clude information on inter- 
facing your "house con- 
troller" (see "Computerize a 
Home," January 1980 BYTE, 
page 28) to the H8. 

Bearing in mind that we 
H8 owners are basically 
hardware-oriented, I believe 
that we would be more like- 
ly to construct a project 
than someone who pur- 
chased a system completely 
assembled. Please consider 
the H8 in future articles; I 
am sure that the reception 
will be well worth the 
effort. 
Ted Benglen 

Most computers are equal 
where interfacing is con- 
cerned. If you look closely 
at the bus signals on your 
H8 you will notice a striking 
similarity between their 
names and the names of 



signals on the Apple and the 
Radio Shack TRS-80. The 
BSR interface (trademarked 
"Busy Box") requires an 
I/OWR* strobe (the "*" in- 
dicates a negative-true 
signal), address lines A0 
thru A7, data lines DO thru 
D7, and power. All address 
and data bus lines on the H8 
use inverted logic levels, so 



the circuit of figure 1 is 
necessary to make the 
system compatible with the 
TRS-80 attachment shown 
in the article. 

1 generally try to list 
signal inputs so that ex- 
perimenters will not be 
discouraged by a title that 
says "TRS-80" or "Apple. " 
For simple input and output 



ports, the signals are often 
easily accessible and com- 
patible among systems. 
Steve 



A Bit of Music 

Dear Steve, 

As a composer/performer, 
I found your article "Sound 



Figure 1 

H8 SIGNALS 
A7 [TT>- 



A6 36 



• HID>- 



A4[3£>- 



A2 [32>- 



1/0 WR [7P> 



+8V (Tir>- 



r 



ICl 
74LS04 



j£* 



-^ 4 



H>8. 



'«-' 



11 



*£& 



GROUND [J~J>- 



;0.22^F 



ft? 



10/»F 
'16V 



TRS-80 COMPATIBLE SIGNALS 
FOR CONNECTION TO BUSY 
BOX INTERFACE 



-T->A7 



LOW ORDER 



-| > A3 

■O A2 




^>A1 
-["> AO J 



\ >■ I/O WR (OUTPUT STROBE) 



f->D7 
fj> D6 
f->D5 

Dm 

O ° 3 
OD2 

O M 

Odo 



. DATA OUTPUT 
( BUS 



Number Type +5V GND 

IC1 74LSC4 14 7 

IC2 74LS04 14 7 

IC3 74LS240 16 8 



-| >■ + 5V SUPPLY 



-| >■ GROUND 



238 August 1980 © BYTE Publications Inc 



Circle 189 on inquiry card. 



Circle 190 on inquiry card. 



FREE Catalog 

New 4-way relief from problems with 
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1. One-stop shopping. 

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MICRO B-FBreaks The Access Barrier. 

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The Complete DataBase Management System for your 8080/Z80 CP/M® System 

You tell Vulcan DBMS what you want done with your data, not how to do it. Vulcan DBMS currently is being used to handle name and ad- 
dress lists, form letter mailing, task scheduling, finance management, telephone lists, and inventories just to name a few. Entire application 
systems can be built up rapidly by using the interactive capability to design the application and then saving the commands as programs for 
future use. Specialized needs for data access can be done instantly using the interactive capability. 
FEA TURES 

* Easy to learn, easy to use English-like commands 

* Full-screen data entry and editing for most 24 X 80 terminals 

* User customizable full screen formatting for input or display 

* Indexed sequential organization of databases permits very fast access of selected records (Vulcan DBMS uses B-tree's) 

* Two separate databases can be processed at once 

* The only microcomputer DBMS that can implement a relational database model 

* Report writer allows subtotaling and summary reports 

* Up to 32 fields per data record 

* Plus all the features of Vulcan DBMS version 1.5 including: 

* written in assembly language for fast execution 

* records of up to 1000 characters 

* databases can be up to 65,535 records long 
Requires a 48K or larger CP/M® system 

Vulcan DBMS on diskette $490 

Vulcan DBMS Users Manual $ 25 

S C D P 

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Tujunga, CA 91042 (213) 352-7701 



VISA . Mastercharge . COD .Check 
California Residents add 6% sales tax 



CP/M S is a registered trademark of Digital Research 
Vulcan DBMS is not associated with Harris Corporation 



Circle 191 on inquiry card. 



BYTE August 1980 239 



PA7[> 
PIN L 



PA1[> 
PIN D 



i_r 



PAOO 
PIN C 



_TL 



SERIAL 
INPUT_ 

IC1 
74LS95 



RT 
SHIFT 

M 



1 



12 



SERIAL 
INPUT 
IC2 
74LS95 



Qa 



Qb 
Qc 
Qd 



X 



12 



SERIAL 
INPUT 

IC3 
74LS95 

Qb 
Qc 

. Qd 



7 



11 



NO^-, 



Figure 2 



IC4 
74LS95 



Qa 
Qb 
Qc 
Qd 



1 



10 



IC5 Q A 
74LS95 

Qb 
Qc 
Qd 

1 2 M 



8 9 



11 



10 



IC6 
74LS95 

Qb 
Qc 
Qd 

1 2 M 



■H 



9 

m 



12 



10 



+ 5V 



36 



23 25 



RESET A8 



DAO 
DAI 
DA 2 
DA3 



IC7 
AY-3-8910 



DA 4 
DA5 
DA6 
DA7 



BC1 
BC2 

BDIR 



A9 A B C 



X 



38 



000 



Number 


Type 


+ 5V 


GND 


IC1 


74LS95 


14 


7 


IC2 


74LS95 


14 


7 


IC3 


74LS95 


14 


7 


IC4 


74LS95 


14 


7 


IC5 


74LS95 


14 


7 


IC6 


74LS95 


14 


7 


IC7 


AY-3-8910 







Off" (July 1979 BYTE, page 
34) quite intriguing. The 
potential of computer- 
controlled music generation 
inspired me to purchase a 
Commodore PET, but the 
tones generated by my 
rudimentary system are not 
exactly musical. 

I would appreciate any 
improvements and sugges- 
tions you might have. The 
limiting factor in my case, 
and I am sure this is true for 
others, is lack of proficiency 
with the instrument. 
Jack Hobson 

My talents are geared 
more toward building the in- 
strument than making music 
on it. If you are reasonably 
adept at building circuitry, 
there is a way to run the 
General Instrument 
AY-3-8910 Programmable 
Complex Sound Generator 
from the parallel user port 
02) of the PET. The clock- 
ing of the integrated circuit 
is not critical, only the se- 
quence of events, but the 
circuit does require 11 bits 
of information. 




UCSD* System for TRS-80 Model II 

The most portable operating system now supports FORTRAN. Pascal and/or FORTRAN modules are compiled in universal P-code, so they 
can run on most microprocessors, often without recompiling. Programs execute up to 10 times faster than comparable BASIC programs, and 
use much less memory. Ready to run on TRS-80 Model II (64K). 

FEATURES PLUS, from PCD Systems 



■ Interactive operating system-dynamic 
overlays, disk file handling, run-time sup- 
port and block I/O routines. 

■ Fast, one pass compilers. 

■ Two Editors— one screen oriented for pro- 
gramming and text editing, one character 
oriented Tor hard copy terminals. 

■ File handler to manipulate disk files. 

■ Macro-assembler that produces code for 
linking with Pascal or Fortran programs. 

■ Linker for link-editing of object and as- 
sembly code modules. 

■ Library of program modules and utilities. 



i Disk formatting program to initialize dis- 
kettes in single or double density formats. 

■ Configuration program for serial I/O. 

■ Disk-set program to permit separate as- 
signment of density and format charac- 
teristics for each disk drive. 

DOCUMENTATION 

■ UCSD System Manual (400 pages). 

■ Beginner's Guide To UCSD Pascal. 

■ Pascal User Manual & Report. 

■ Fortran User's Manual with Fortran 
systems. 



PCD Systems, Inc. 

PO Box 143 PennYan, NY 14527 315-536-3734 



PRICES 

■ UCSD System with Pascal Compiler $350 
with Pascal and Fortran Compilers $500 

■ Fortran Compiler alone 

(requires Version II.O) $200 

■ P-Code Interpreter alone 

(either LSI-11 orZ-80) $ 85 

Optional Utility Programs 

■ CP/M* to Pascal file conversion $ 50 

■ TRSDOS* to Pascal file conversion $ 50 

■ Z-80 Disassembler/Dump program $ 50 

ALSO AVAILABLE 

■ UCSD System for MINO or PDT». 

■ Z-80 Adaptable System (you write BIOS). 

■ UCSD System for CP/M environments. 

PCD Systems is a licensed distributor of the 
UCSD System for Pascal and Fortran. Dealer 
inquiries are invited. 



"Trademark of the Regents of the University of California 'Trademark of Tandy Corporation 'Trademark of Digital Research 'Trademark of Digital Equipment Corporation 



240 August 1980 © BYTE Publications Inc 



Circle 192 on inquiry card. 



Circle 194 on inquiry card. 



Circle 195 on inquiry card. 



P&T CP/M® 2<S<TRS-80 MOD II 
versatility! 

P&T CP/M 2 is customized to take maximum advantage ot the 
Mod II hardware and still be compatible with standard CP/M. 

So What? There are hundreds ot applications programs available 
(from dozens of sources) to run under CP/M and most of them can 
run unmodified on the Mod II with P&T CP/M 2. 

So Why P&T CP/M 2? When you compare CP/M'sforthe Mod II 
you will find that P&T CP/M 2 is way out in front of the pack. We 
were the first to offer 596K bytes (610,304 bytes) of storage at 
double density. We have the most advanced screen driver with 
features like cursor addressing, insert/delete line, optional non- 
scrolling lines, change cursorsize and blink, clear to end of line of 
screen, read cursor position, read character at cursor, and more. 
We also support a time of day clock, a user supplied real time 
interrupt routine, and the Line Printer III. Our serial port drivers 
support, ETX/ACK, XON/XOFF, and status line (CTS and DCD) 
handshaking. 

Ok • What about documentation? We supply the 7 standard 
Digital Research manuals for CP/M plus our own 150 page 
manual describing in detail how to use P&T CP/M 2. 

What's all this cost? ONLY $185! 

We also carry: MAGIC WAND text processor $350 

CBASIC2 (improved performance) $105 

PASCAL/M $175 

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Contact us for latest information. 

Prepaid COD, Mastercharge or Visa orders accepted. 
Shipping extra, California residents add 6% sales tax. 



fKoOf 



PICKLES & TROUT 

P.O. BOX 1206, GOLETA, CA 93017. (805) 967-9563 



CP/M is a trademark of Digital Research Inc. 



TRS-80 is a trademark ot Tandy Corp 




»ar 



BoardsforS-IOOBUS 
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"INTERFACE: 1" 

Serial, Parallel, ROM, RAM, 
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Features: MODEL - 3SPC 

• 3-Serial with hardware UARTS, RS232-C or20ma Current loops 

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• Built in 4K ROM, 4K RAM Capability with SW disables 
(for 2708s, 2114's, ROM, RAM not supplied) 

• Built in Kansas City cassette interface usable to 1200 BAUD 

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Fully socketed, solder masks, gold contacts, and guaranteed for one full year. 

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O.E.M. PRICING AVAILABLE, DEALER INQUIRY INVITED 

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S.C. Digital 



MAKE YOUR BASIC 

ilN 



Developing business applications without keyed file support is like 
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Enter MAGS AM™ 

MAGSAM picks up where your BASIC leaves off by providing it 
with a powerful Keyed File Management System that's quick and 
easy to use. The result is applications that do exactly what you want 
them to — instead of only what BASIC allows you to. 
Supporting Cast 

MAGSAM's advanced features and capabilities include: 

• Random, sequential, and generic access by key 

• Secondary indexing with any number of keys 

• Key and record deletes with automatic space reclamation 

• Dynamic file allocation and extension 

• Complete compatibility with BASIC files 

• Interactive tutorial program 

• One year update service 

The versatile MAGSAM file management is now available in two 
major versions. MAGSAM IV, the new high performance assembler 
version, is ideal for business applications in which response time is 
critical. Complete with an interface for CBASIC, MAGSAM IV is 
$295. MAGSAM III is the standard version and is in use world wide. 
Written in BASIC, it is available for CBASIC, Microsoft BASIC, or 
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You're the Star 

MAGSAM is available immediately —off the shelf. So you can begin 
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Circle 196 on inquiry card. 



Circle 197 on inquiry card. 



BYTE August 1980 241 



The circuit of figure 2 
here uses only 74LS95 4-bit 
parallel-access shift registers. 
IC1, 1C2, and 1C3 are 
paralleled to form a 12-bit 
shift register, and IC4, IC5, 
and IC6 make up a 12-bit 
latch. By setting the ap- 
propriate logic level on bit 7 
of the user port, the infor- 
mation will be loaded into 
the 12-bit register when a 



high/low/high transition 
occurs on bit 1. When 12 
bits have been loaded, a 
low/high/low transition on 
bit can be used to latch 
the binary value and 
stabilize the information 
while more is loaded. 

The fast action of the shift 
and store operations should 
be fairly transparent to the 
AY-3-8910, which should 



operate as described in the 

article. 

Steve 



A Bit More Music 

Dear Steve, 

I read with interest your 
article on the AY-3-8910, 
and I am presently building 
the interface for my 



Southwest Technical Pro- 
ducts 6800 system. Do you 
intend to publish any soft- 
ware for the 6800-based pro- 
cessors that will drive the 
circuit? 
Arnold Pung 

The AY-3-8910 is made by 
General Instrument on Long 
Island (600 W John St. 
Hicksville NY 11802). They 



Figure 3 



120 VAC 



£ 



FUSE 



RECTIFIER/ 
CHARGER 



12 TO 48VDC Tt 
STORAGE J 
BATTERY 



FUSE 
-&*\jt>— 



SOLID 
STATE 
INVERTER 



BYPASS 
i SWITCH 



^r 



^»- 



-o 



120VAC 

TO COMPUTER 



-o 



Power to the Computer 

Dear Steve, 

I would like to suggest a 
possible future subject: 
backup power for micro- 
computers. I am very in- 
terested in home control and 
security, but the more 
responsibility and power I 
give my system, the more 
strongly I feel that it should 
have an uninterruptible 



power source (UPS). 
Stanly W Pozeisky 

Thank you for your sug- 
gestion. I have also been 
considering uninterruptible 
power supplies. I have a 
26 K-byte Z80 computer 
running 24 hours a day, and 
an UPS is a requirement. 
Unfortunately, when we 
start talking about run- 
ning the computer and disk 



drives, we start talking 
about quite a bit of power. 
This could conceivably re- 
quire several hundred watts, 
so a system similar to those 
used in commercial installa- 
tions might be in order. (See 
figure 3.) 

This system uses battery 
backup, with a large in- 
verter to supply normal AC 
during an outage. Designing 
power inverters is an art in 



itself, and considerable care 
must be taken so as not to 
run afoul of the FCC radio- 
frequency interference (RFI) 
standards. While I mull this 
over, you might want to ob- 
tain a copy of the February 
1980 issue of Digital Design 
for a good article on the 
subject. 
Steve 



Control Your Life! 

Now have full computer control of up to 256 lights, appliances and 
even wall switches without special wiring. The SciTronics REMOTE 
CONTROLLER permits direct control of the inexpensive BSR remote 
line-carrier switches sold by Sears, Radio Shack and many others. 

• Controls all 256 BSR remote switches — not just 16 

• Hardware driven — requires minimum software 

• No ultrasonic link — prevents erractic operation 

• No BSR command module necessary 

The controller comes complete with full documentation, sample software 
and is designed to work with most of the popular computers including 
any S-100 based system, TRS-80-1, Apple II, Heath HB and others 

Applications: 

• Make your entire home or apartment computer controlled 

• Save energy by controlling lights & appliances 

• Control security systems & alarms 




Remote switches not included 

CONTROLLER BOARD (S-100) $159. 

ENCASED CONTROLLER (TRS-80, Apple, etc.) $184. 

Send check or SciTronics Inc. 

money order to: S2t s ciivvhi si . PO BOX r .W4 

HtlHIIHbM. PA 1B01S 

(21 1) 868-7220 
please list system with whu h you plan to use controller Master Charge and Visa 
,K cepted PA residents add sales tax 

Real Time Clock Available. Please Inquire. 



242 August 1980 © BYTE Publications Inc 



Circle 198 on inquiry card. 



Circle 199 on inquiry card. 



Circle 200 on inquiry card. 



DATA DISK 
SYSTEMS 



CP/M* FOR NORTH STAR SYSTEMS 

CP/M 1.2 - The induslry standard 'software bus' specially tailored tor the North Star disk systems and 8080, 8085. ZBO nwocompulers 
Fully supports all MandarD North Star I/O and single, double or quad capacity disk drives A minimum ol 24K ol continuous Mm memory starting 
at local on ;ero is required The following Oigiial Heseaicti |rjf) and Datadisk Systems |dd| programs are included on your CP'M rjiskette 

tS150/J?5 



ED (Or) - Ten Editor Used to write uro- 
grams m most languages and modily any 
ASCn flisk Me Delete substitute, search on 
ciUT'Strtng/line numoer/ relative positicn 
block move, giooai change, macro com- 
mands ED is your window lo CP'M com- 
patible 'oltware 

KM \ot) - tojo hssemoier Uses stan- 
dard 8080 mnemonics and pseudo-ops 
Condilional SSMfflbly, HEX lile generation, 
assemble listings multi-drsk lile transfer 

PlP(df) — Peripheral interchange Program 
File transfer between disk and logical 
Devices Software file routing, concatin- 
anon. [agination, tent e>traction. case 
conversion, line numbering and much more 

SUBMIT (dr) - 



ODT(dr) - Dynamic Oeouggmg Tool 8080 
assembly language run-lime monitor Real 
time between break pornls. tracing, full in 
ternai register display and alteralion at any 
step, single slep, disassembly, assembly. 
the list goss on and on if you write device 
controllers. DDT is an invaluable tool 

STAT (dr| - Status/alteraiion of logical-lo- 
physical devices, disk drive parameters, 
storage space, file size. 

LOAD (On- Convert 8080 'HEX' tiles (oul 
put ol ASM) into machine eieculabie code 
Programs are then e«ecutea by typing 
Itic progran name 



SYSGEN (on - Create new sysiem diskello 



DSTAT fdd - Multi-purDOsc Disk status 
routine Logically assign disk drives to 
operate with any combination ol single den- 
sity, double density, single side, double 
side, as well as stanOard or sequential disk 
sectoring An oplionai selection allows last 
stepping and optimal sectoring lo srgmli- 
canlly reduce Oisk-inlensivc program 
execulion line 

An arJHilional fealure permits sysiem re- 
configuration lo quad capacity This allows 
douoie density owners to upgrade wilh no 
additional sell ware expense 



XSUB Idil - Extends me power ol SUBMIT 
lo include ailomaiic line input to programs 



FOLLOWING SOFTWAHE AVAILABLE IN MOST 5.25 AND B INCH FORMATS 

MT mlcioSYSTEMS PASCAL/MT - req 
Symbolic debugger BCD or floating :oi 
environment Produccscompacimachme 



sas/sis 

S45/SS 

S7D/S15 



OESPOOl - Simultaneous life print and user operation 
TEX-T«Itormaller Ouahly hard copy 



SID - Symbolic instruction debugger Mullipi 
Hack, histogram source code labels 



lsSlDfor1IWH0ir.5trur_l.on si 



COMPILER SYSTEMS CBASIC-2rel 2 06 
Compiler extended dtsk BASIC Self 
protection, line numoeis nol leguired 



California residenls add 6X sales tax 

Specify single double or quad capacity 

Addilionai format; available soon 

Structurec Systems Group programs require CP'M and CBASIC-2 

•CP/M is i regtuorea naiiemirk ol Dignsi Reses<ch 

ISotfware anil tiMumentation 'documenWion only 

Cmicf 



STflUCTUHEO SYSTEMS negu.resCBASIC-Zl 
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13 2 MBYTE 
26 -I MBYTE 



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n lor the CP/M 

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S695/S25 
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$95/510 
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Shipping 5? 0' 



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una 



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8" DISK CONTROLLER 

NOW— DOUBLE SIDED OPTION! 

• DOUBLES APPLE ][ STORAGE 

• APPLE DOS COMPATIBLE 

• SHUGART 800 OR 850 COMPATIBLE 

• IBM 3740 DATA ENTRY CAPABILITY 

• CP/M, UCSD PASCAL CAPABILITY 
Available at your local APPLE Dealer: $400. 



£SVA> 



SORRENTO VALLEY ASSOCIATES 

11722 SORRENTO VALLEY RD. 
SAN DIEGO, CA 92121 



THE BEST OF BOTH WORLDS 

NORTH STAR BASIC - CP/M 

The Fabulous North Star Basic Meets 
The Industry Standard CPjM Operating System 

Not all perfect marriages are made in heaven; this one 
was made in SoHo! The software professionals at the 
SoHo group present The MATCHMAKER, an easy-to- 
use conversion kit which enables North Star owners 
who also own the CP/M operating system to gain the 
full power of their North Star Basic, running under 
CP/M. 

You'll have dynamic file allocation, automatic file 
creation and extension, and automatic reuse of 
deleted files, all under the control of the powerful in- 
struction set of the outstanding North Star Basic inter- 
preter with its byte-access or random files, multiline 
functions, and extensive library of software. 32K 
memory is all you need. No relocation or modification 
of Basic is necessary. And all your existing North Star 
programs will run without modification! 

The installation takes about 30 minutes and involves 
no disassembly or machine coding. Every powerful 
feature of both systems is maintained with this profes- 
sional piece of software. And the instructions are 
COMPLETE and easy to follow. 



The SoHo Group 

140 Thompson St. 

Suite 4-B 

New York, NY 10012 



The MATCHMAKER 

$89.95 ppd. 

Manual only, $9.95 

applicable 

against purchase 



NY residents include sales tax 
Note: CP/M and North Star are registered trademarks of Digital Research and 
North Star computers, respectively. 



IEEE-488 BUS 

SYSTEM BUILDING BLOCKS 

For Commodore PET/CBM and other computers... 




TNW-1000 

TNW-2000 

TNW-232D 

TNW-103 

SOFTWARE 

^/tnw 

CORPORATION 



TNW-2000 



Serial Interface: $129 

1 channel output only 

Serial Interface: $229 

1 channel input ana output 

Dual Serial Interface: $369 

2 channels input and oulput plus RS-232 control lines 

Telephone Modem: $389 

Auto answer/aulo dial. Use wilh DAA 

PTERM: A program that turns vour PET into a terminal 
(Use with TNW-2000, TNW-232D, or TNW 1 03) 

SWAP: Allows storage ol up to 8 programs in PET 
memory at once Run them in any order. 

PAN: A sophisticated electronic mail program 
(use with TNW-103) 

Write or call (or information today: 

TNW Corporation 
3351 Hancock Street 
San Diego CA 92110 



(714) 225-1040 



Circle 201 on inquiry card. 



Circle 202 on inquiry card. 



BYTE August 1980 243 



Circle 203 on inquiry card. 



the electric pencil II 

for the TRS-80 Model II* Computer 



The Electric Pencil is a Character Orienred Word Processing 
System. This means that text is entered as u continuous string 
of characters and is manipulated as such. This allows the user 
enormous freedom and ease in the movement and handling of 
text. Since lines ore not delineated, any number of char- 
acters, words, lines or paragraphs may be inserted or deleted 
anywhere in the text. The entirety of the text shifts and 
opens up or closes as needed in full view of the user. Car- 
riage returns as well as word hyphenation ore not required 
since each line of text is formotted automatically. 

As text is typed and the end of a screen line is reached, a 
partially completed word is shifted to the beginning of the 
lollowing line. Whenever text is inserted or deleted, existing 
text is pushed down or pulled up in a wrap around fashion. 
Everything appears on the video display screen as it occurs 
thereby eliminating any guesswork. Text may be reviewed at 
will by variable speed or page-at-a-time scrolling both in the 
forward and reverse directions. By using the search or the 
seorch and replace function, any siring of characlers may be 
located and/or replaced with any other string of characters as 
desired. Specific sets of characters within encoded strings 
may also be located. 

When text is prinled, The Electric Pencil automatically 
inserts carriage returns where they are needed. Numerous 
combinations of Line Length, Page Length, Character Spacing, 
Line Spacing and Page Spacing allow for any form to be 
handled. Right justification gives right-hond margins that 
are «ven. Pages may be numbered as well as titled. 



the electric pencil 

.) Proven Wurtl Procetsinq Sysiem 




The TRSDOS versions of The Electric Pencil II are our bos! 
evw! You con now type as fast as you like without losing any 
characters. New TRSDOS features include word left, word right, 
word delete, bottom of page numbering as well as extended 
cursor controls for greater user flexibility. BASIC files may 
also be written and simply edited without additional software. 

Our CP/M versions are the same as we have been distributing 
far several years and allow the CP/M user to edit CP/M files 
of our CONVERT utility for an additional 
is not required if only quick and easy word 
A keyboard buffer permits fast typing 



with the addition 
S35.O0. CONVERT 
processing is required, 
without character los: 

Serial Diablo, NEC, C 
All other printers . . 



CP/M TRSDOS 

.me $ 300.00 $ 350.00 
... $ 275.00 $ 325.00 

The Electric Pencil I is still available for TRS-BO Model I 
users. Although not as sophisticated as Electric Pencil II, it 
is still an extremely easy to use and powerful word processing 
system. The software has been designed to be used with both 
Level I (I6K system) and Level II models of Ihe TRS-80. Two 
versions, one for use with cassette, and one for use wilh disk, 
are available on cassette. The TRS-BO disk version is easily 
transferred to disk and is fully interactive with the READ, 
WRITE, DIR, and KILL routines of TRSDOS. 

TRC Cassette $ 100.00 

TRD Disk $ 150.00 



Features 

TRSDOS or CP/M Compatible ■ Supports Four Disk 
Drives * Dynamic Print Formatting ■ Diablo, NEC & 
Qume Print Packages * Multi-Column Printing ■ Print 
Value Chaining • Page-ot-a-time Scrolling < 
Bidirectional Multispeed Scrolling * Subsystem with 
Print Value Scoreboard » Automatic Word & Record 
Number Tally ' Global Search & Reploce • Full Margin 
Control • End of Page Control • Non Printing Text 
Commenting ■ Line & Paragraph Indentalian * 
Centering * Underlining • Boldface 




ss 



MICHAEL SHRAYER SOFTWARE, INC. 

1198 Los RoblesDr. 

Palm Springs. CA. 92262 

(714) 323.1400 



are the people to contact 
about particular applications 
of that device. If you write 
or call (516) 733-3107, direct 
your inquiry to the product 
manager associated with tlie 
circuit. 

It is important to talk to 
the right person since one 
manager may not be 
familiar with another's pro- 
duct line. As most com- 
panies do, General Instru- 
ment Corporation puts out a 
large amount of application 
literature. 
Steve 



No More Scanner 

Dear Steve, 

I have been reading BYTE 
for over a year now and I 
find your Circuit Cellar 
articles useful and infor- 
mative. I would like to read 
your article "I've Got You in 
My Scanner: A Computer- 
Controlled Stepper Motor 
Light Scanner," November 
1978 BYTE, page 76. I am 
writing you because this 
article is no longer available 



through BYTE's back-issue 

department. Can you direct 

me to a source for this 

article? 

Walter A Filimon 

Thank you for the vote of 
confidence. There are a 
number of sources you can 
use for articles of BYTEs 
past: BYTE often has back 
issues which are available 
for the cover price plus 
postage. Give BYTE a call 
on their toll-free number 
(800) 258-5485; they'll be 
glad to help. If your interest 
is specifically in my articles, 
let me suggest that you pick 
up a copy of the compen- 
dium book Ciarcia's Circuit 
Cellar, volume 1, from 
BYTE Books. It contains 
most of my articles, in- 
cluding the November 1978 
one. It has the extra advan- 
tage that any proof errors in 
the original articles are cor- 
rected. BYTE Books may be 
contacted at 70 Main St, 
Peterborough NH 03458. 
Steve! 



Micro Computer Your One Stop For. . .Quality and Huge Saving* 

DISCOUNT 

COMPARE : 



^^r M.\mJ ^^^ ^»—^ ^ f X j M, Company 

COMPARE PRICE^tQUALlTY-^DELIVERY^cSERVICE 
you'll know why you don't have to look anywhere else! 

fy APPLE fOMPIICOlOB J^f 



CALIFORNIA DATA CORPORATION'S 

VERSATILE 

S-100 ANALOG I/O SYSTEMS 



r A 

i. * 

r i 



APPLE 

M 6K Apple II or Plus $ 960 

48K Apple II or Plus 1075 

Disk w/Controllcr 539 

'Disk 450 

k-Pascal 495 

ATARI 

400 * 475 

fgOO 777 

I Disk 595 

APF ELECTRONICS 

k APF Computer * 495 

.JVCENTRONICS PRINTERS 

^^X 730-1 Parallel $ 695 

r 730-1 Serial 735 

•779-2 Tractor 995 

•704 Serial 1695 

700 Parallel 1095 

COMMODORE PET 

8K "N" $ 695 



1595 
1695 






16K"N"or"B" 850 

32K-N"or"B" 1095 

2040 Floppy 1095 

2022 Printer (Tractor) 6 '5 

8016 1325 

8032 1575 

8050 1495 

C2 "N" Cassette add $89.90 

AIL ORDER ONLY 



COMPUCOLOR 

16K 

32K 

CROMEMCO 

System 3 * 544. 

Z-2H 944: 

HAZELTINE 

1210 * 825 

1500 109! 

INTEGRAL DATA 

440 (Paper Tiger) $ 

440-Graphics 929 

INTERTEC 

•SuperBrain 32K $ 2495 

32K memory upgrade with purchase 

$19.95 
•SuperBrain 64K 269! 

NEC SPIN WRITER 

•5530 RO $2695 

•5520 KSR 2990 

•5510 RO 2795 

Tractor add 200 

TEXAS INSTRUMENTS 

99/4 Computer $1095 

810 Printer 1695 

XEROX TERMINALS 

•1740 RO $ 2619 

•1740KSR 3000 

■1750 RO 2800 

•1750 KSR 3170 

Tractors add 235 

PHONE (212) 986-7690 



* 



Send Certified Check (Personal or Company Checks require 2 weeks to clear.^ 
We pay all shipping and insurance charges except items marked with asterisk" 
VISA, MasterCharge add 5% N.Y.S. Residents add appropriate sales tax. 

Micro Computer Discount Co -<de^ rreMs 

60 E. 42nd St.. Suite 411, New York. N.Y. 10017 



9^ 

95 r 

10 r 

MX 

5 r 

k. 

9 r 
5 r 

fc 

C^ 




16 Channel A/D 
2 Channel D/A 
4 Channel D/A 



rmimTimmiiiniiimiiiiilirni 



High quality commercial grade S-100 bus compatible systems are 
designed for industrial and laboratory use. 

• 16 channel 12 bit A/D conversion system nominally 
operates at 25 kHz 

•12 bit resolution, ± the LSB accuracy 

• Multiplexer, converter, and sample and hold on the 

hybrid chip 

• 7 control and measurement ports 

• Utilizes Z80 and 8080 interrupt modes 

• Optional Programmable Gain Instrument Amplifier 

allows mixing of high and low level signals 

• 2 and 4 channel D/A high-speed conversion systems 

• Binary and 2's complement inputs 
•Outputs: ±5v, ±10v, to -lOv, or to +10v 
•Replaceable output amplifiers protect circuit 

• 2 channel board has 16 bit parallel I/O and scope 

intensification strobe 

• A/D's from $575 D/A's from $395 



CDC 



CALIFORNIA DATA 
CORPORATION 

3475 Old Conejo Road, Suite C10 
Newbury Park, California 91320 
(805)498-3651 



244 August 1980 © BYTE Publicabions Inc 



Circle 204 on inquiry card. 



Circle 205 on inquiry card. 



Circle 206 on inquiry card. 



FOR SERIOUS USERS 

OF 8080, 8085, OR Z80 COMPUTERS 

PRINTER WIZARD - Now add powerful capabilities to 
your printer. Free your computer for use while 
simultaneously printing backlogged output on a first-in- 
first-out basis. Transparent operation without noticable 
slowing of the computer. Allows continuous computer and 
printer operation on programs having sporadic output. Will 
backlog up to 100 pages when used with a disk system. 
Adds optional automatic paging with numbers, adjustable 
margins on 4 sides, indented overflow lines. Occupies less 
than 2% K. 



Documentation only 



EX80M103 
EX80M103D 



$45.00 
$ 7.50 



DISASSEMBLER — Disassemble machine code into stan- 
dard source language. Modify or relocate existing programs 
such as DOS or BASIC using your existing assembler (not 
included). Disassembles any 8080, 8085, or Z80 code, in- 
cluding embedded data blocks and "trick" codes. 
Generates symbol and label tables. 



Documentation only 



EX80M217 
EX80M217D 



$75.00 
$12.50 



ALL EXCOM products are fully supported and warranted indefinitely against 
original defects. Available on single or double density NORTHSTAR 5'A" 
diskettes, 300 or 1 200 baud cassettes (specify). Washington residents add 
5.3% tax. 

Excom 

P.O. Box 1802 Bellevue, Washington 98009 U.S.A. 
Telephone (206) 641-6577 



TM 



6009 2H00 "k 

SINGLE BOARD COMPUTER 

• MEETS I.E.E.E. S-100 STANDARD 

<£> • 10 addressing modes 
s? • 24 indexed sub modes 
^p • auto increment/decrement 
• constant indexing from PC 

• 4K/8K/16K ROM • 2K RAM 

ROM / RAM relocatable on 4K boundary 

• ACIA; PIA; 8080 SIMULATED I/O 

• 20 PARALLEL I/O LINES • 256 I/O PORTS 

ACIA provides RS-232 lines for asychronous com- 
munications with limited modem control at 8 select- 
able baud rates; I/O beatable at any 4K boundary 

• COMPREHENSIVE MANUAL WITH 
SOFTWARE LISTINGS 

• P.C. BOARD: SOLDERMASKED WITH 
PARTS LEGEND 

P.C. Board & Manual $69.95* + shipping 

• adsMON: ADS MONITOR SUPPORTS 
BREAKPOINTS 

User definable interrupt service & more. 

Available in PROM, write for prices. 
Illinois residents add sales tax. "add $1.00 for shipping & handling 

Ackerman Digital Systems, Inc. 

110 N. YorkRd., Suite 208, Elmhurst, 111.60126 (312)530-8992 




He'sjust completed production on our new 
36 page catalog and he's exhausted. 

So, rather than put him right back 
to work on our August 2 page 
spread, we're giving him a break. 

Look for our regular ad in Septem- 
ber. In the meantime, send for our 
brand new free catalog. It's the 
most complete in the industry. 

COMPUMARf 

270 Third St. Cambridge, Mass/ J 02142 
^ Dept.108 /jf 





BUY COMPUTERS 
BY MAIL ORDER 
AND SAVE 16% 



APPLE 

16K $ 958.00 

32K $1,040.00 

48K $1,100.00 

Disk with Controller 

$ 495.00 
Disk $ 440.00 

Pascal $ 445.00 



DYNABITE 

Save 15% 

CROMEMCO 

System 3 $5,890.00 

VERBATIM 
& MEMOREX 

5V4 " — . $27.50 



NORTH STAR 

Horizon-2-32KDD 

Memory 16K 
32K 

HAZELTINE 

1400 
1410 
Add Regent 25 

Send certified check 

(regular checks require 2 weeks to clear) or 

charge to VISA or Master Charge. Customer pays shipping. 

MIRO COMPUTERS, INC. 

27 Long Meadow Place, South Setauket, L.I., N.Y. 11720 

(516) 423-7955 



$2,390.00 
$ 389.00 
$ 579.00 



$650.00 
$710.00 
$925.00 




Circle 312 on inquiry card. 



Circle 207 on inquiry card. 



BYTE August 1980 245 



Circle 209 on inquiry card. 



Circle 208 on inquiry card. 



CP/M SOFTWARE 



^v 



ADAPT 2.00 

Runs Cromemco Software UnderCP/M 1,4 or 2,2 $75 

Get Cromemco software to run on your CP/M Version 1.4 or 2.2 system. 
ADAPT interfaces most of those powerful Cromemco packages to any 
Z-80 based CP/M system without patching. ADAPT works without 
changes for any memory size. 

RATFOR-80 

Fast RATFOR Language (RATional FORtranj $95 

RATFOR-80 lets you write structured code that translates to Microsoft or 
Cromemco FORTRAN. TSWs RATFOR-80 JRATional FORlran) pre- 
compiler runs at more than 1000 statements per minute. Price includes 
extensive subroutine library. Documentation includes "Software Tools" 
book by Kernighan and Plauger. (ADAPT and RATFOR packages 
combined $150) 

FMT 

FMT Word Processing Text Formatter for CP/M $75 

FMT works with any CP/M editor to give you automatic page headings 
and footings, page numbering, centering, underscoring, external file 
merging, and in-line console input. FMT works with any video, CRT, or 
hardcopy terminal and printer combination. With daisy-wheel printers, 
FMT provides superscripting, subscripting, and half-line spacing. 



THE SOFTWARE WORKS 

8369 Vickers 

San Diego, CA 92111 

(714) 569-1721 



VISA and MiisliTCharRt accepted. 
' CP/M is u trademark '>f Distill Research. 




Business Software 
in Micropolis Basic 

DATASMITH announces the availability of two 
new turnkey business systems designed 
especially for MICROPOLIS-Based computers, 
including the VECTOR MZ. Both systems are 
completely menu driven and highly interactive, 
so they can be used effectively by your present 
office staff. 

• GENERAL LEDGER. Everything you need 
to keep the books. Features easy-to-use 
data entry and error correction, trial bal- 
ance, posting, and a variety of comprehen- 
sive reports. Automatic error detection 
keeps the books in balance. Writes checks 
and makes journal entries in one operation. 

• PAYROLL. A very flexible system that 
adapts to a wide variety of needs. Features 
federal, state, and local tax calculations, 
EIC credit, and special pay and deduction 
amounts. Prints all necessary reports, pay- 
checks, and W-2 forms. 

Put your computer to work with these compre- 
hensive systems now. Call or write for complete 
details. Custom services also available. 

DnTflSMiTH 

1 5501 West 1 09th St., Lenexa, KS 6621 9, (91 3) 888-8486 



"L. 



Zo-SYSTEMS 

3 ZOBEX 



Complete computer on 3 S- 100 boards with 

32K RAM for Under $1000.00* 

Runs M/PM and C/PM 



Low power, 

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Bank select in I6K sections 

Can be disabled in 4K increments 

2 or 4 serial ports, 3 parallel, one 4K 
EPROM, Vectored interrupts, real time 
clock, Software controlled baud rates, 
Drives daisy wheel printer directly 

All digital design for stable and 
reliable performance. No one- 
shots or analog circuitry. BIOS for 
C/PM available. 

6 slot shielded motherboard 
for good cooling and low noise. 



64K RAM 


4 MHz 


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2-4 MHZ 
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DISK CONTROLLER 

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6 months warranty on our hoards with norma! use 

Z S -SYSTEMS / ZOBEX 

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P.O. Box 1847, San Diego, Ca. 92112 

(714)447-3997 

introductory offer for limited lime only 



(F 



A Message 
to our Subscribers 



From time to time we make 
the BYTE subscriber list 
available to other companies 
who wish to send our 
subscribers promotional 
material about their products. 
We take great care to screen 
these companies, choosing 
only those who are reputable, 
and whose products, services, 
or information we feel would 
be of interest to you. Direct 
mail is an efficient medium 
for presenting the latest 
personal computer goods and 
services to our subscribers. 

Many BYTE subscribers 
appreciate this controlled 
use of our mailing list, and 
look forward to finding 



information of interest to 
them in the mail. Used are 
our subscribers' names and 
addresses only (no other 
information we may have is 
ever given). 

While we believe the 
distribution of this 
information is of benefit to 
our subscribers, we firmly 
respect the wishes of any 
subscriber who does not want 
to receive such promotional 
literature. Should you wish to 
restrict the use of your name, 
simply send your request to 
BYTE Publications Inc, Attn: 
Circulation Department, 
70 Main St, Peterborough NH 
03458. Thank you. 



^z 



J 



246 BYTE August 1980 



Circle 210 on inquiry card. 



Circle 211 on inquiry card. 



Circle 213 on inquiry card. 



FORTH 

VER. 1.7 FOR APPLE II* COMPUTERS * 

100 PAGE, PROFESSIONALLY WRITTEN MANUAL 

FORTH INTEREST GROUP COMPATIBLE 

. DIRECT HOT-LINE TO SYSTEM DEVELOPERS 

INCLUDES ITS OWN DOS 

CA>P'N SOFTWARE HAS DELIVERED 100's OF 

WORKING FORTH SYSTEMS 

UPDATE OFFER: TRADE IN YOUR VER. 1.6. DISK 

FOR FULL CREDIT OF PURCHASE 

PRICE TOWARD VER 1.7 

RUNS ON APPLE II OR APPLE II+ WITH 

1 OR MORE DISKS AND 48K. 

ALSO RUNS ON LANGUAGE CARD 

AVAILABLE AT COMPUTER STORES OR 

DIRECTLY FROM CAP'N SOFTWARE 
PRICE, SYSTEM $140, MANUAL ONLY $20 

CAP'N SOFTWARE 

P.O. BOX 575 

SAN FRANCISCO, CA 94101 




ALSO AVAILABLE FOR PDP-11f 

COMPATIBLE WITH VER. 1.7 FOR APPLE 
DOWNLOAD PROGRAM DEVELOPMENT 

OR EXECUTION 
RUNS STAND-ALONE OR UNDER RT-11, 1 
RSX-11Mt, OR RSTSt 
AVAILABLE DIRECTLY FROM CAP'N SOFTWARE 
PRICE, SYSTEM $145, MANUAL ONLY $20 



it 



"Trademark ol Apple Computer Corp. tTrademark of DEC. 



Introducing ...the NEW 
....H-P 85 Peripherals. 






1 




HEWLETT 
PACKARD 

Hewlett-Packard's New Peripherals 
Are Available Now. 

Suggested retail prices 

HP-85A Computer '3250.00 

HP 7225A Graphics Plotter 2050.00 
HP 2631B Opt. 885 Printer 3650.00 
HP-IB Interface Module 395.00 

• WE MEET ANY PRICE IN THE NATION 




FARNSWORTH 
COMPUTER CENTER 

1891 N. Farnsworth Ave., Aurora 
(immediately S. of E-W Tollway) 

Phone (3 12)-85 1-3888 
Weekdays 10-8; Sat. 10-5 




BYTE 

BACK ISSUES 

FOR SALE 



The following issues are available: 

1976: July and November 

1977: March, May thru December 

1978: February thru October, December 

1979: January thru December except March 

1980: January thru June except February 

Cover price for each issue thru August 1977 is $1.75 

Domestic; $2.75 Canada and Mexico; $3.75 Foreign. 

September 1977 through October 1979 Issues are $2.50 

Domestic; $3.25 Canada and Mexico; $4.00 Foreign. 

November 1979 to current is $3.00 Domestic; $3.75 Canada 

and Mexico; $4.50 Foreign. 

Send requests with payment to: 

BYTE Magazine 

70 Main St, Peterborough, NH 03458 

Attn: Back Issues 







H 



IS THERE A 



GAP 



IN YOUR LIFE 



GAP General Accounting Package. Fantastic double 

entry accounting system with user definable ac- 
counts. The account numbers are made up of 7 
4-digit fields allowing 7 levels of account 
classifications. With the use of the Operator 
Report Selector Generator (OSRG), you can 
generate any type of report you desire, or use 
report programs in GAP-GL, GAP-AP, and 
GAP-AR. 

GAP-GL Includes all basic GAP functions, plus entry of 
General Ledger transactions, prints General 
Journal, General Ledger summary and detail, 
Balance Sheet, Profit and Loss. 

Price $124.95 

GAP-AR Requires GAP-GL to run, allows adding A/R in- 
voices, printing Sales Journal, detail A/R report, 
Account Aging, add/update Cash Receipts with 
register, Cash Receipts Journal, and A/R Billing. 

Price $99.95 

GAP-AP Requires GAP-GL to run, allows adding of A/P 
invoices, printing Purchase Journal, detail A/P 
report, Aging of Accounts, Check Writing, 
Check Printing, Cash Disbursements Journal. 

Price $99.95 

System requirements are 32K CP/M CP/M is registered trademark of Digital Research 

PROFESSIONAL DATA SYSTEMS 



% 



318 E 18 St. 

BAKERSFIELD CA. 93305 

(805) 323-0891 



Circle 214 on inquiry card. 



BYTE August 1980 247 



What's New? 



PERIPHERALS 



Printer Uses Plastic and 
Metallized Daisy Wheels 
Interchangeably 

A series of serial impact printers that 
produce typewriter-quality output for 
word processing, data processing, and 
communications applications has been 
announced by Diablo Systems Inc, 
24500 Industrial Blvd, Hayward CA 
94545, (415) 786-5207. The Model 630 
daisy-wheel printers use plastic and 
metallized print wheels interchangeably, 
with print speeds from 32 to 40 cps 
(characters per second) depending on the 
type of print wheel, type style, and text. 
Model 630 printers accept all Diablo and 
Xerox plastic and metal print wheels. 
Friction and pin-feed platens and other 
paper-handling options are offered. The 
630 series supports the RS-232C/V.24 
interface for communications applica- 
tions, and a microprocessor interface 
that permits direct attachment of the 
printers to a variety of small office and 
data processing systems. The price is 
$860 in original equipment manufac- 
turer's (OEM) quantities of 500. 

Circle 490 on inquiry card. 




An RS-232 Card Reader 

The Model 121-4 card reader is 
capable of reading any common 
punched or marked card and includes 
serial RS-232 or card image output (with 
Hollerith-to-ASCII conversion if 
necessary), parallel 20 mA current-loop 
output, self-clocking on both marked 
and 80-column punched cards, or opera- 
tion with printed strobe marks on either 
side of the card. The 121-4 may be set 
for card feed-through at 6 ips (inches per 
second), or automatic return of cards to 
the front after reading. This card reader 
also has a self-test feature which enables 
the user to check sensor accuracy. The 
Model 121-4 operates on either 50 or 60 
cps (characters per second) and sells for 
approximately $520 in original equip- 
ment manufacturers quantities. For more 
information, contact HEI Inc, Jonathan 
Industrial Center, Chaska MN 55318, 
(612) 448-3510. 

Circle 492 on inquiry card. 



Removable Disk Cartridges for CDC and Ampex Drives 





The 4420 is a removable disk cartridge 
for use on Control Data's cartridge 
module drive (CMD) 9448 series and 
equivalent disk drives. The product is 
capable of storing up to 16 megabytes of 
data. The disk cartridge uses one surface 
to record data and one surface to func- 



tion as a dedicated servo reference. Den- 
sity is 348 tracks per inch, with 823 
tracks per surface. The cartridge is 
available with factory formatting. For 
information, contact Nashua Corpora- 
tion, 44 Franklin St, Nashua NH 03061. 
Circle 491 on inquiry card. 



Two Printers from Facit 

Facit Inc, 66 Field Point Rd, Green- 
wich CT 06830, has developed two 
printers, the 4520 and the 4542. The 
4520 is a bidirectional printer with a 
speed of 100 cps (characters per second) 
and a noise level of less than 60 dB. The 
4520 is microprocessor-controlled, with 
a 100% duty cycle. The printer utilizes 
a 9-by-9 dot matrix, while accom- 
modating paper-roll or fanfold forms. A 
serial or parallel interface is included. 
The unit price is under $1000. 

The 4542 provides the full graphic 
capability and control of Facit's 9-by-9 
matrix Stored-Force Flex Hammer Head. 
It features two-color printout, gray scale, 
and proportioned spacing. All European 
versions, Katakana, APL, and Libris 
character sets are available. The 4542 
lists for under $4000. 



Circle 493 on inquiry card. 



Modem Eliminator 

International Data Sciences Inc, 7 
Wellington Rd, Lincoln RI 02865, (401) 
333-6200, has introduced the Model 
6100 modem eliminator. The unit allows 
interconnection of data-terminal equip- 
ment without modems. It can be used in 
asynchronous or synchronous modes, 
and with terminals configured for half- 
or full-duplex operation. The IDS 
modem eliminator also eliminates the 
need for two back-to-back modems 
operating within a short distance. 
Features include internal strap selections 
for primary and secondary RTS/CTS 
delays, ring memory functions, and 
clock source. Data-terminal equipment 
can be located up to 50 feet from the 
modem eliminator, allowing a maximum 
separation of 100 feet. Its DTE interface 
conforms to EIA RS-232C and CCITT 
V.24 standards. The Model 6100 is 
priced at $360. 

Circle 494 on inquiry card. 



Where Do New Products Items Come From? 

The information printed in the new products pages of BYTE is obtained from 
"new product" or "press release" copy sent by the promoters of new products. If in 
our judgement the information might be of interest to the personal computing 
experimenters and hotnebrewers who read BYTE, we print it in some form. We 
openly solicit releases and photos from manufacturers and suppliers to this 
marketplace. The information is printed more or less as a first in first out queue, 
subject to occasional priority modifications. While we would not knowingly print 
untrue or inaccurate data, or data from unreliable companies, our capacity to 
evaluate the products and companies appearing in the "What's New?" feature is 
necessarily limited. We therefore cannot be responsible for product quality or com- 
pany performance. 



248 Augusl 1980 © BYTE Publications Inc 



What's New? 



MISCELLANEOUS 




Computhink Unveils 
Small-Business Computer 

Computhink Inc, 965 W Maude Ave, 
Sunnyvale CA 94086, (408) 245-4033, is 
now offering Minimax, a microcomputer 
system designed for small businesses and 
independent software organizations. The 
Minimax can store over 100 K bytes of 
internal memory. By using various con- 
figurations of floppy-disk drives, the 
system can have an on-line disk storage 
capacity ranging from 800 K to 4.8 
megabytes. A 6502 microprocessor is 
used in the system. The system features 
full-screen data entry, field protect and 
automatic skip to the next field, and 
split screen operation. The Minimax, 
with 800 K bytes of disk storage, has a 
suggested retail price of $7770. A con- 
figuration with a printer is under 
$10,000. These prices include business- 
applications software. 

Circle 495 on inquiry card. 



Introducing the QDP-100 
System 

This product is a Z80A-based S-100 
machine. The single-board unit contains 
the microprocessor; two serial and two 
parallel ports; a double-sided, double- 
density disk controller for 5- and 8-inch 
floppy-disk drives; an Intel-like 2716 
programmable read-only memory 
(PROM) burner; a real-time clock; and a 
2 K-byte monitor. The operating system 
is CP/M 2.2. A 4 MHz, 64 K-byte 
dynamic memory board is also supplied. 
The video display is a "smart" terminal 
with 80-character by 24-line display, a 
25th status line, reverse video, blinking 
and half-intensity characters, protected 
and unprotected fields, and other 
features. The display uses a Z80 
microprocessor for display operation. A 
hard-disk system can be integrated into 
the system. Accounting, data-base 
management, word processing, real 
estate, statistics, and other software 
packages are offered by Quasar. The 
price for the QDP-100 is $4795. Details 
are available from Quasar Data Pro- 
ducts Inc, 25151 Mitchell Dr, North 
Olmsted OH 44070, (216) 779-9387. 
Circle 496 on inquiry card. 



A Printer from Mauro 

Mauro Engineering, Rt 1, Box 133, Mt 
Shasta CA 96067, (916) 926-4406, has 
introduced the MP-250 PROAC pen 
plotter. It uses standard paper sizes and 
plots at speeds of up to 2.5 inches per 
second with 0.005-inch resolution. The 
standard machine uses one parallel out- 
put port and comes with full-vector 
driver software for 8080, 6502, and 6800 
microprocessors. Interfaces are available 
for the TRS-80, Apple, and serial data 
ports. The MP-250 can be used for 
graphics, schematics, music composi- 
tion, architectural drawings, and other 
applications involving plotting. The 
MP-250 costs $650. 
Circle 497 on inquiry card. 




Computer Devices 
Announces Self- 
Prompting, Portable 
Computer 

A portable, self-prompting computer 
for the nontechnical user has been 
developed by Computer Devices Inc, 25 
North Ave, POB 421, Burlington MA 
01803, (617) 273-1550. The Miniterm 
model 1206/PAT operates through the 
use of preprogrammed application 
modules. The computer is aimed at in- 
dustrial, commercial, and financial 
clients. The 1206/PAT includes 32 K 
bytes of programmable memory. The 
application programs are written in 
either BASIC or Motorola 6800 
assembly language. Other standard 
features of the computer include an 
80-column, 50-character per second ther- 
mal printer; 5-inch floppy-disk drive; 
built-in modem; and acoustic coupler. 
The unit weighs 7.3 kg (17 pounds). The 
price for the computer is $5195. 
Circle 498 on inquiry card. 



EPROM Programmer with 
RS-232 Interface 

This erasable programmable read-only 
memory (EPROM) programmer, Model 
EP-2A-87, with RS-232 and 20 mA loop 
interfaces, has been introduced by Op- 
timal Technology Inc, Blue Wood 127, 
Earlysville VA 22936, (804) 973-5482. 
The programmer includes a 2 K- or 
4 K-byte buffer which can be loaded or 
read by another computer in the on-line 
mode. Data rates are 110 and 1200 bps 
(bits per second). In the off-line mode, a 
keyboard enables the operator to pro- 
gram, verify, and check if the EPROM 
is erased, and load the buffer from 
EPROM. EPROMs may be copied in the 
off-line mode by first loading the buffer 
from the programming socket. A built-in 
self-test includes provisions for checking 
the buffer and whether the EPROM will 
enter the high-impedance state. Priced at 
$600 with a 4 K-byte buffer, personality 
modules are $16 to $35 for programming 
various EPROMs on the market. 
Circle 499 on inquiry card. 



6502-Based Single-Board 
Computer 

Compas Microsystems, 224 S E 16th 
St, Ames IA 50010, (515) 232-8187, has 
announced CSB 2, a stand-alone module 
based on the 6502 microprocessor. The 
board is compatible with the Rockwell 
System 65 bus standard. EXORcisor- 
based cards may be used with CSB 2 
with minor modifications. CSB 2 in- 
cludes a 6502 microprocessor, 2 K bytes 
of static programmable memory, four 
sockets for Intel 2716 or 2764 erasable 




programmable read-only memory 
(EPROM) integrated circuits, one VIA 
(6522), one PIA (6520), and one ACIA 
(6551). CSB 2 provides 30 input/output 
(I/O) lines, ten buffered output lines, 
two interval timers, input latching on 
peripheral ports, an RS-232 port with 
data speeds from 110 to 19,200 bps (bits 
per second), and up to 32 K bytes of 
EPROM space. CSB 2 is priced at $395 
and the manual is available for $4. 
Circle 500 on inquiry card. 



August 1980 © BYTE Publications Inc 249 



What's 



MISCELLANEOUS 



Nuts & Volts 

Nuts & Volts is a new publication 
serving amateur radio and computer 
enthusiasts. It is devoted exclusively to 
classified and display advertising for 
new and used equipment. Items are 
categorized for easy reference, and there 
are sections for business opportunites 
and wanted items as well. Classified ads 
are SO. 10 per word with a $2 minimum 
charge. Typesetting and art services are 
available for display advertisers. Nuts & 
Volts is available monthly for a one- 
time charge of $5 from Nuts & Volts 
POB 1111, Placentia CA 92670. 
Circle 538 on inquiry card. 



Reset Extender for TRS-80 

The Reset Extender is an aid for 
TRS-80 owners who have trouble access- 
ing the Reset button in the back of the 
keyboard. Most TRS-80 owners use a 
pencil to hit the Reset button. With little 
effort, the Extender attaches to the hood 
and simplifies reset tremendously. The 
Reset Extender is available from Em- 
manuel B Garcia Jr & Associates, 203 N 
Wabash, Rm 2102, Chicago IL 60601, 
(312) 782-9750, for $3.99. 
Circle 501 on inquiry card. 



Microprocessor-C ontr oiled 
Floppy-Disk Drive and 
Controller 

The System 2000/10 is a 
microprocessor-controlled floppy-disk 
drive and controller that plugs into the 
Teletype Model 43, the Texas In- 
struments Silent 700, and similar 
typewriter terminals. The System 
2000/10 can operate as a stand-alone 
word processor, or as an on-line, 
storage, edit, and forward unit. In the 
on-line mode, the data rate is capable of 
reaching 9600 bps (bits per second). In 
the on-line mode, it can be invisible to 
the host computer. The system can also 
be used with ADM-3A, Televideo 912, 
and similar video displays. A software 
package includes global search and 
global replace commands. Options in- 
clude extra programmable memory up 
to 64 K bytes, a printer port, Telex in- 
terface, BASIC and IBM 3740 com- 
patibility. The price for the System 
2000/10 is $1695. Contact Terminal 
Data Corporation, 11878 Coakley Cir, 
Rockville MD 20852, (301) 881-7655. 



Circle 502 on inquiry card. 




Memory and Expansion Module for TFs 16-Bit Board 



George Goode & Associates Inc, 
12840 Hillcrest Rd, Suite 113, Dallas TX 
75230, (214) 980-0730, is offering a 
Memory and Input/Output (I/O) Expan- 
sion Module (MEM) for the Texas In- 
struments University Module 16-bit 
microcomputer board. The MEM ex- 
pands the University Module's memory 
by an additional 8 K bytes and expands 
I/O address space by an additional 480 
bits. An erasable programmable read- 
only memory (EPROM) programmer 



with software driver, cables, and 
integrated-circuit components are in- 
cluded. The MEM includes sockets for 
up to 8 K bytes of EPROM and 8 K 
bytes of programmable memory, two 
44-pin connectors for I/O expansion, 
with space for an additional thirteen 
connectors, and an EPROM programmer 
for TMS 2708 and 2716s. The MEM is 
priced at $299, including a manual. 

Circle 503 on inquiry card. 




Commercial Calculators 
from Texas Instruments 

Texas Instruments has announced a 
family of heavy-duty commercial 
calculators incorporating the Seiko 350 
mechanical printer. Ranging in price 
from $160 to $205, the TI-5213, -5215, 
-5217, and -5219, have been designed for 
operator comfort and reliability. Each 
model features two-key rollover and 
10-level keyboard buffering. The printer 
delivers 2.8 lines per second using stan- 
dard 5.8 cm (2.25 inch) paper and prints 
up to twelve digits plus commas, 
decimal point, and two-column audit 
trail. Other features common to all four 
models include multiplication and divi- 
sion by a constant, automatic computa- 
tion of percentage calculations, indepen- 
dent add register, grand total register, 
grand total on/off switch, decimal selec- 
tor, automatic rounding, and item 
count. Inquiries should be addressed to 
Texas Instruments Inc, POB 10508, M/S 
5889, Lubbock TX 79408. 
Circle 504 on inquiry card. 



Serial Communications 
and Control on a Single 
Card 

Vantage Data Products has developed 
a single-card computer for use in com- 
munications and control applications. 
The 280-based card is used with serial 
input/output (I/O), parallel I/O, pro- 
grammable memory, and erasable pro- 
grammable read-only memory 
(EPROM). Serial communications are 
asynchronous RS-232 and programmable 
to all standard data rates up to 5600 bps 
(bits per second). Modem-control func- 
tions are also included. Power re- 
quirements are +5 V and +12 V. 
Negative voltage for RS-232 communica- 
tion is generated on the card. Options 
include a software-monitor program on 
EPROM for operation of the computer 
with a terminal, and single power- 
supply options. The suggested retail 
price is $195. Contact Vantage Data 
Products, 550 W 200 South, Suite 8, 
Provo UT 84601, (801) 377-6687. 
Circle 505 on inquiry card. 



250 August 1980 © BYTE Publications Inc 



Wtraft New? 



MISCELLANEOUS 




Floppy-Disk Drive Power Supplies 



Powertec Inc, 20550 Nordhoff St, 
Chatsworth CA 91311, (213) 882-0004, 
has introduced the FD series of floppy- 
disk, dual-output power supplies. The 
FD101 delivers main channel outputs of 
+ 5 V at 0.75 A and secondary channel 
outputs of +12 V at 1.8 V. The FD101 
offers flexible strap-selectable inputs of 
103-127/206-254 VAC, single phase 47 
to 440 Hz. Standard features include 
overvoltage, overload, short circuit and 
reverse voltage protections, no turn-on 
or turn-off overshoot, and a one-year 



warranty. The supplies provide line 
regulation of ±0.5% for a ±10% input 
line change, and static loads of 50 to 
100%. Load regulation for the units is 
±0.5% on all outputs for a to 100% 
load change, 5 mV peak-to-peak max- 
imum ripple, 0.03 °C temperature stabil- 
ity over full operating ranges and 0.3% 
drift for a 24-hour period. Transient 
response is less than 50 ms for a 50% 
load change. Contact the company for 
prices and availability. 
Circle 506 on inquiry card. 




Bidirectional Totalizer 

The DigiTec Model 8222 bidirectional 
totalizer is used for counting functions 
in industrial processes or product-test 
systems where up-down counting is re- 
quired. All up-down counting functions, 
with count direction control, are user- 
programmable. Operating modes include 
totalizing two inputs by adding and/or 
subtracting one from the other based on 
phase relationship or logic input. Soft- 
ware response ensures that every pulse is 



added or subtracted even during 
simultaneous occurrence. The Model 
8222 is available with either a 5- or 
7-digit LED (light-emitting diode) 
display. Both models offer polarity and 
overflow indication. The unit is 4.8 by 
18 by 19 cm (1.89 by 6.6 by 6.86 
inches), and the cost is $415 for the 
5-digit model and $467 for the 7-digit 
model. Address inquiries to United 
Systems Corporation, 918 Woodley Rd, 
Dayton OH 45403, (513) 254-6251. 
Circle 507 on inquiry card. 



A Talking Voltmeter 




This talking voltmeter allows users to 
keep their eyes on the probes and avoid 
shocks, short circuits, and blown in- 
tegrated circuits. It is also an aid for the 
visually handicapped. The dual 
microprocessor-based system provides 
voltage readings that are automatically 
announced via an internal 3-inch 
speaker every 7 seconds, or upon 
operator command. A slave processor 
selects the speech elements that are re- 
quired by the measurement, while the 
main processor controls the system 
timing and signal processing. The instru- 
ment is powered by a rechargeable nicad 
battery pack. It weighs 1.1 kg (2.5 lbs) 
and measures 6.2 by 25.5 by 23 cm (2.5 
by 10 by 9 inches). An earphone jack is 
provided for work in noisy en- 
vironments. Options include an LCD 
(liquid-crystal display), current and 
resistance measurement circuits, and a 
serial interface for recording the digital 
output on audio cassette recorders. 
Foreign languages are also available. 
The price is $395. For details, contact 
the Franklin Institute Research 
Laboratory Inc, The Benjamin Franklin 
Pky, Philadelphia PA 19103, (215) 
448-1340. 
Circle 508 on inquiry card. 



The Connection 

The Connection is a modem designed 
for TRS-80 Models I and II. It eliminates 
acoustic couplng, so line sensitivity is in- 
creased and transmission errors are 
reduced. The RS-232 port provides the 
means to simultaneously run a printer or 
input data from a keyboard. It features 
a data rate of 300 bits per second (bps), 
single and duplex mode, direct connec- 
tion of wires between telephone and 
computer, software, and instructions. 
For further details on The Connection, 
contact The micro-Peripheral Corpora- 
tion, POB 529, Mercer Island WA 
98040. 
Circle 509 on Inquiry card. 



August 1980 © BYTE Publications Inc 251 



MISCELLANEOUS 




The Hobby-Blox System 

Hobby-Blox is a breadboard system 
that allows the user to customize the 
board to fit projects. The system in- 
cludes plug-in tie points, interchangeable 
modules, color-keyed and cross-indexed 
modules. There are two starter packs; 
one for discrete component projects, the 
other for integrated circuits projects. 
The system includes 14 modules that can 
be purchased individually, most with a 
suggested retail price below $3. The 



modular packs include a tray, terminal 
strips, distribution strips, discrete strips, 
bus strips, display strips, LED (light- 
emitting diodes) strips, vertical tray, 
speaker panel, control pane!, blank 
panel, battery holder, binding post 
strips, and tray extender clips. The two 
starter packs are priced under $7. For in- 
formation, contact A P Products Inc, 
1359 W Jackson St, Painesville OH 
44077. 
Circle 510 on inquiry card. 



SDI Graphics Interface 

The Cromemco SDI is a high- 
resolution graphics interface designed for 
use in Cromemco computer systems. 
The SDI displays color or black-and- 
white images with up to 756-by-484 
point resolution. It features color map 
selection, dual page windowing func- 
tion, automatic area fill mode, and 
NTSC broadcast compatibility. The SDI 
consists of two circuit boards that plug 
directly into the S-100 bus of any 
Cromemco microcomputer system. Each 
pixel of the display may be mapped 
from one nybble or from one bit of the 
display memory. Twelve or 48 bytes of 
memory may be used for the display 
memory, allowing four basic modes of 
operation. In nybble-mapped mode any 
16 of 4096 possible colors may be 
displayed in a single picture. In bit- 



mapped mode any two of these colors 
may be displayed in a single picture. For 
black-and-white nybble-mapped mode 
there can be 16 shades of grey. A bit- 
mapped black-and-white picture yields 
only a black-and-white display. The 
three outputs of the device can display 
three different pictures to three different 
black-and-white monitors simultaneous- 
ly. The SDI sync signals adhere to the 
RS-170 standard for the television 
broadcast industry. The SDI can be syn- 
chronized to external television equip- 
ment through the use of an external 
composite RS-170 sync signal, a com- 
posite video signal, or external horizon- 
tal and vertical sync signals. The SDI 
graphics interface is available for $595 
from Cromemco Inc, 280 Bernardo Ave, 
Mountain View CA 94043, (415) 
964-7400. 
Circle 511 on Inquiry card. 



Winter 1980 Catalog from 
Inmac 

Twenty-four new computer supply 
and accessory products are featured in 
Inmac's Winter 1980 catalog. The new 
offerings include preformatted floppy 
disks, thirteen Clear Signal microcom- 
puter cables, sound enclosures designed 
to keep noise in and dust out, floppy- 
disk hanging file folders, and mini data- 
cartridge binder leaves. For a free 
subscription to the full-color catalog, 
call or write Inmac, Dept BPR, 2465 
Augustine Dr, Santa Clara CA 95051, 
(408) 727-1970. 

Circle 512 on inquiry card. 



Computer Products from 
Electronic Systems 

A catalog featuring systems by Apple, 
Radio Shack, Atari, Compucolor, and 
other companies is available from Elec- 
tronic Systems, POB 21638, San Jose 
CA 95151, (408) 448-0800. Electronic 
Systems also sells products for S-100 bus 
systems, tools, software, terminals, and 
many other items. The catalog includes 
prices and order forms. 
Circle 513 on inquiry card. 



Vector Offers Electronic 
Packaging Catalog 

Vector Electronic Company's catalog 
has complete details on the company's 
electronic-packaging products, tools, 
and kits. Emphasis is placed on micro- 
computer-interface boards for all con- 
ventional buses, a variety of card cages 
and cabinets, breadboarding com- 
ponents, plus numerous sockets and ter- 
minals. Price lists are included along 
with the names and the addresses of 
Vector's distributors. Contact Vector 
Electronic Company, 12460 Gladstone 
Ave, Sylmar CA 91342, (213) 365-9661. 
Circle 514 on inquiry card. 



The Hayden 1980 
Computer Science Catalog 

This publication contains the complete 
selection of Hayden titles on everything 
about computers from introductory in- 
formation and programming to software 
and advanced technology. It is available 
from Hayden Book Company Inc, 50 
Essex St, Rochelle Park NJ 07662, (201) 
843-0550. 
Circle 515 on Inquiry card. 



252 August 1980 © BYTE Publications Inc 



Circle 177 on inquiry card. 



What's New? 



MISCELLANEOUS 



The Z-88 Processor Card 

Trie 2-88 offers 16-bit processing 
power to S-100 bus users. The card 
combines a Z80A and an 8088 
microprocessor to allow access to all 
currently available 8080 software 
without the need to translate into 8086 
machine language. The 8088 is fully 
software compatible with the 8086, so 
all 16-bit software, such as Microsoft 
8086 BASIC, will run on the Z-88. The 
Z-88 features an 8-bit data bus that uses 
existing products without modification; 
direct memory address of 16 megabytes; 
selectable IEEE Preliminary Standard or 
Altair/Imsai S-100 bus; no wait states 
with 450-ns memory access; vectored or 
noninterrupting modes that transfer con- 
trol between processors; a 1 K-byte 
phantom read-only memory (ROM) 
which initializes the microprocessor; and 
an 8-level TTL (transistor-transistor 
logic) priority-vectored interrupt. The 
cost to build a Z-88 is around $450. For 
more information, contact the designers 
at Programmers Publishing Company, 
POB 2571, Kalamazoo MI 49003, (616) 
344-9323. 



Circle 516 on inquiry card. 



FORTH for Four Levels 

FORTH is available from Ancon, 
17370 Hawkins Ln, Morgan Hill CA 
95037, (408) 779-0848. There are four 
levels offered for the following; the hob- 
byist; the personal high-level language 
programmer who wants a ready-made 
editor and some basic utilities; the 
engineer in the microprocessor- 
development laboratory creating pro- 
ducts; and the commercial original 
equipment manufacturer (OEM) or 
sophisticated end-users. The commercial 
level includes files, data-base manage- 
ment, source data entry, teleprocessing, 
distributed processing, and accounting 
packages. The hobby versions are for 
the TRS-80 with cassette for $29.95; 
Heath H8-H89 for $49.95; 8080-based 
systems with an 8-inch floppy disk for 
$49.95; and 6809-based systems with a 
5-inch FLEX floppy-disk drives for 
$49.94. Personal systems include TRS-80 
for $45.95 for cassette and S65.95 for 
floppy-disk systems; Apple II disk for 
$99.95; KIM-1 for $90; and 8080 
systems with CP/M and 8-inch disks for 
$125. Industrial systems are available for 
the EXORcisor, Rockwell System 65, the 
Intel MDS, 8080 with CP/M, Apple II, 
and others. Commercial levels are made 
for Digital Equipment Corporation 
PDP-11 and VAX, Data General Nova 
and Eclipse, IBM Series 1, and others. 
Circle 517 on inquiry card. 




Intel MDS-Compatible 
10-Megabyte Storage Unit 

Advant Corporation, 696 Trimble Rd, 
San Jose CA 95131, (408) 946-9300, has 
introduced a 10-megabyte Winchester 
hard-disk data storage unit. Interfacing 
with all Intel MDS models, the 
MicroSupport Model 105 data storage 
unit utilizes Shugart 8-inch Winchester 
hard disks. The MicroSupport 105 
features built-in error correction, a 
microprocessor-based controller, and a 
power supply. For more information, 
contact the Advant Corporation. 
Circle 518 on inquiry card. 



Books from MIT Press 

Systems theory, computer sciences, 
artificial intelligence, programming 
languages, information, communication, 
and control are the topics covered by a 
variety of books published by the MIT 
Press. The new catalog also contains 
series and classified listings. For a copy 
of Computer, Science, Engineering, con- 
tact the MIT Press, 28 Carleton St, 
Cambridge MA 02142. 
Circle 519 on inquiry card. 



Software for the Atari 800 

Atari 800 software is now available 
through Sebree's Computing. Atari's 
3-Dimensional Graphics Package, for 
$29.95, will run on 8 K- or 16 K-byte 
machines. It features multiple-color con- 
trol, selectable resolution, line clipping 
and pushing, telephoto and wide angle 
views, four program listings, and a 
manual. Using one of the four pro- 
grams, the user can input any scene, 
rotate it and view it from any location 
in three-dimensional space or even from 
inside of it. Wumpus Adventure is a 
mixture of two popular games that has 
color graphics and sound effects. The 
user can control arrow direction and ac- 
tion during the battles. The program is 
designed for the 16 K-byte unit and 
costs $14.95. Contact Sebree's Com- 
puting, 456 Granite Ave, Monrovia CA 
91016, (213) 359-8092. 
Circle 520 on inquiry card. 



ThesubLOGIC 

FS1 

Flight Simulator" 







ou7:«r-5in:m-fOK:iT*T«SM 



is just one 
application of 
our fine 
graphic 
software. 

Other 

applications 
can be yours ! 

Choose from a coordinated software 
and hardware collection to fit your 
graphic needs . . . 

SOFTWARE 

A23D1 animation package for the 
Apple II ($45 on cassette, $55 for disk). 

8080/Z80 3D package for most S100 
systems ($41 on tarbell cassette or 
paper tape, $51 on 5" North Star disk, 
or $52 on 8" CPM disk). 

HARDWARE (S100) 
Godbout $399 

Matrox ALT-256 $395 

Matrox ALT-51 2 $595 

Micro Angelo $1095 

Panasonic Color Monitors $450 & up 

Write or call for an informative catalog 
describing these and other graphic 
products and their easy use in your 
applications. 

Most subLOGIC software is at your 
dealer's. If he doesn't stock it, order 
direct from subLOGIC. Add $ 1 .25 for 
UPS or $1 .75 for first class mail. Visa 
and Mastercharge accepted. 

*The FS1 Flight Simulator is available 
for Apple II and TRS-80 Level I & II 
for $25 on cassette. 

(217)359-8482 ■ /"\^N|AV 

•rm^LOGIC 

^.A^ilL^y Distribution Corp. 

BoxV, Savoy, I L 61874 

The engineering and graphics experts. 



August 1980 © BYTE Publications Inc 253 



What's New? 



SOFTWARE 



Suprdump for the TRS-80 

Definitive Micro Systems, 20 Glen- 
wood Cres, St Alberta, Alberta T8N 
1X5, Canada, have announced Supr- 
dump, a disk dump/modify utility for 
the TRS-80 Model I. Suprdump is 
designed to expedite the debugging of 
programs utilizing disk files. It can also 
create disk-file test data. The utility will 
dump a specified disk sector onto the 
video screen in a hexadecimal plus 
ASCII (American Standard Code for In- 
formation Interchange) format. 
Modification of the information on disk 
is accomplished by typing over the 
displayed data. Suprdump is supplied on 
a floppy disk for $29.95. 
Circle 521 on inquiry card. 



The Magic Wand 

The Magic Wand is a word-processing 
program that provides underscoring, 
boldface, superscripting, and subscript- 
ing in any combination and even all at 
once. Boldface can vary in intensity and 
underlining can be broken or solid. The 
program provides justification, discre- 
tionary hyphens, and other processing 
capabilities. It can also create form 
letters from a mailing list, assist in 
writing standard letters, perform 
variable line spacing, print with true 
proportional spacing, print headers and 
footers on each page, automatic pagina- 
tion, and more. It is written for the 
TRS-80 Model II and requires CP/M. 
The price is $350 from Pickles & Trout, 
POB 1206, Goleta CA 93017, (805) 
967-9563. 
Circle 522 on inquiry card. 



Attach an Apple to a 
Malibu 

The Malibu/Apple Input/Output 
(I/O) card serves as an interface be- 
tween the Apple II and the Malibu 
Model 165 printer. The Malibu card uses 
the Apple's microprocessor to provide 
bidirectional printing, changeable type 
fonts, high-resolution graphics printout, 
and other functions. The card is com- 
patible with Integer BASIC, Applesoft, 
Apple Pascal, as well as Applewriter 
and EasyWriter. The Malibu card uses a 
technique whereby it substitutes its soft- 
ware for the Apple's during printing. 
After the printing is completed, control 
is passed back to the Apple software. 
For further information, contact Malibu 
Design Group Inc, 211109 Nordhoff St, 
Chatsworth CA 91311. 
Circle 523 on inquiry card. 




6800 C Compiler 

Wintek has introduced a C compiler 
for the 6800 microprocessor. The com- 
piler includes the features described in 
the book The C Programming Language 
by Kernighan and Ritchie 
(Prentice-Hall). C is a structured- 
programming language for operating 
systems and numerical, text-processing, 
data-base programs, and other general 
applications. Characters, numbers, and 
addresses can be combined and efficient- 
ly moved about with the 6800 arithmetic 
and logical operations. Consequently, C 
is very efficient in the amount of 6800 
code generated. C provides pointers and 
the ability to do address arithmetic. Any 
function can be called recursively and its 
variables declared in a block-structured 
fashion. Variables may be internal, ex- 
ternal, or global. Functions of a C pro- 
gram can be compiled separately. The C 
compiler is intended to run under the 
Wizrd multitasking disk operating 
system on the Sprint 68 microcomputer. 
The cost for C is $495. The cost for the 
Sprint 68 with 48 K bytes of program- 
mable memory, dual 8-inch floppy-disk 
drives, and Wizrd is $3995. Contact 
Wintek Corporation, 1801 South St, 
Lafayette IN 47904, (317) 742-8428. 
Circle 524 on inquiry card. 



Software for the HP-85: 
The Pro-Organizer 

The Pro-Organizer is for applications 
ranging from a daily appointment 
organizer to an index box for maintain- 
ing name and address lists, to a data 
bank for the professional, executive, 
engineer, or scientist. The program is 
designed for the 16 K-byte HP-85 com- 
puter and is supplied on cartridge. It is 
completely automatic from power turn- 
on. Any data-management requirements 
may be custom formatted. Data may be 
edited easily. Additional cartridges may 
be used to build up a library. The sug- 
gested retail price is $95. For details, 
contact Scelbi Publications, 20 Hurlbut 
St, Elmwood CT 06110, (203) 522-5515. 
Circle 525 on inquiry card. 



Apple FORTH 1.7 

With this FORTH Interest Group- 
compatible system, Apple users can 
define operations and enter them as 
components of the language. Machine- 
language subroutines can be entered 
directly from the keyboard, where they 
are assembled immediately and ready to 
run or test. Apple FORTH 1.7 includes a 
screen editor that can be customized. It 
has facilities to manufacture turnkey 
disks which boot directly into user ap- 
plications. FORTH is its own operating 
system and debugger, including compile- 
time checks. Progams run faster than In- 
teger BASIC, and object code is very 
compact. This language is compatible 
with the FORTH International Standard, 
so programs can be run on 8080- and 
PDP-11-based systems. A 48 K-byte 
Apple II or Apple II Plus with one or 
two disk drives is required. The price is 
$140, including a manual, from Cap'n 
Software, POB 575, San Francisco CA 
94101, (415) 848-6913. 
Circle 526 on inquiry card. 



polyFORTH 



polyFORTH is an operating system 
for microprocessor-development systems 
and minicomputers. polyFORTH pro- 
vides the compiler, interpreters, 
assembler, character editor, virtual 
memory, and multitasking capability 
within its 8 K bytes of memory. Ap- 
plications programs can be coded com- 
bining high-level with low-level 
languages. Program-development time is 
cut down because the interactive pro- 
gramming environment allows rapid 
testing and debugging. Memory re- 
quirements for complex applications are 
reduced to as little as half that of 
assembler programs and to about 10% 



that of other high-level languages. Run 
speed is controlled by the programmer. 
Time-critical routines can run at full 
machine speed. All versions of 
polyFORTH are compatible with a 
minimal number of machine-dependent 
features. The language features 16-bit 
arithmetic on all systems, as well as 
32-bit capacity. For $2500, users receive 
polyFORTH on a floppy disk, a set of 
programmable read-only memory 
(PROM) integrated circuits containing 
the precompiled system, two manuals, 
and access to a hot line service and 
newsletter. Contact FORTH Inc, 2309 
Pacific Coast Hwy, Hermosa Beach CA 
90254, (213) 372-8493. 
Circle 527 on inquiry card. 



254 August 1980 © BYTE Publications Inc 



10 Megabyte Hard Disk 



> 



• 





5440-12 Top Load Drive 
* Factory rebuilt 10MB cartridge disk drive only 
A new Cameo Data Systems controller is available for $1,495 
$4,495 for a brand new Ampex 10MB drive only 





We are the CP/M** and MP/M" specialist of South- 
ern California. We can supply you with the latest CP/M 
($150) or MP/M ($300) and with Standard BIOS ($150) 
or Custom BIOS ($300). Immediate delivery worldwide. 
Domestic and foreign inquiries invited. ..dealers too. 
"CI' Mand Ml' M arc Trademarks ofDicital Research 



We are a full service computer retailer. We totally inte- 
grate hardware and software into high quality, high reli- 
ability systems. Systems for use in development, process 
control and general business. Word processing naturally, 
multi tasking and multi processing too. 



Computer Components 



Circle 215 on inquiry card. 



5848 Sepulveda Boulevard Van Nuys, California 9141 1 213*786-741 1 



BYTE August 1980 255 



Wbsrts New? 



SOFTWARE 




SBC-FORTH on EPROM 

This implementation of FORTH can 
run in many of Intel's and National's 
line of SBC-80 microprocessor cards. It 
runs stand-alone and requires no addi- 
tional memory, input/output (I/O) 
devices, or disks to operate. Standard 
features include a resident compiler, an 
8080/8085 assembler, screen editor, and 
adaptive disk I/O. The disk I/O allows 
a combination of four single-density 
drives or four double-density drives with 
two additional single-density units for a 
total capacity of 2500 screens. The 
system price is $500 including the 
manual Contact Zendex Corporation, 
6398 Dougherty Rd, Dublin CA 94566, 
(415) 829-1284. 

Circle 528 on inquiry card. 



FLEX for Custom 
Hardware 

A new version of the FLEX disk 
operating system is available for users of 
custom or nonstandard 6800 and 6809 
systems. Developed by Technical 
Systems Consultants Inc, POB 2570, 
1208 Kent Ave, West Lafayette IN 
47906, (317) 463-2502, it is fully com- 
patible with most versions of FLEX. 
FLEX supports features such as dynamic 
file-space allocation, random and se- 
quential file accessing, user startup 
facility, user environment control, 
English-language error messages, and 
over twenty commands for normal disk 
operations. This version contains a 
manual describing how to write disk and 
terminal input/output (I/O) routines to 
adapt FLEX to most any hardware. The 
only major system requirement is a soft- 
sectored floppy-disk drive that uses 256 
bytes per sector. When the adaptation is 
complete, the user's system will be 
capable of running any standard FLEX 
software. The $150 price includes the 
FLEX disk with editor and assembler, 
and a set of manuals. 

Circle 529 on inquiry card. 



The Datahandler 

The Datahandler is a data-base 
management system running in 
MMSFORTH on the TRS-80 Model I 
with at least 32 K bytes of program- 
mable memory and one floppy-disk 
drive. Users can specify up to ten data 
fields appropriate to each particular job. 
Standard and special report formats can 
be output to the screen and the printer. 
The Datahandler includes mail-list and 
checking-account programs with custom 
report commands and sample data files. 
It can sort a typical 100-record file in 5 
seconds, and lookups take less than 1 
second. An indexed-key structure incor- 
porates string and value selection 
mechanisms including normal-compares 
and values inside or outside a range. 
One feature allows the program area of 
the Datahandler disk to be software 
write-protected, while the data-file area 
is left open. Regularly used system con- 
figurations may be precompiled for 
5-second loading times. Additions to the 
Datahandler will be a report-generator 
module and a large-data-files module. 
The Datahandler costs $59.90 including 
the PIMS Manual. It also requires the 
MMSFORTH system disk which pro- 
vides its language and operating system, 
which costs $79.95 including an in- 
troductory manual. Contact Miller 
Microcomputer Services, 61 Lake Shore 
Rd, Natick MA 01760, (617) 653-6136. 

Circle 530 on inquiry card. 



SL5 — A Software- 
Development Tool 

SL5 is a software-development tool 
for small systems. It is an interactive 
programming system with an integral 
compiler, interpreter, assembler, disk 
operating system, and library of pro- 
cedures. SL5 is based on the recommen- 
dations of the 1977 FORTH Standards 
Committee. Since SL5 is written in SL5, 
it adapts to most microcomputer 
operating systems. A host-executable 
code kernel, a source-code kernel, and a 
system-generation program are provid- 
ed. The system generation program 
regenerates the kernel from the source or 
generates compact stand-alone read-only 
memory (ROM) object modules. An SL5 
development system requires less than 
32 K bytes of memory. Most applica- 
tions programs require less than 8 K 
bytes. SL5 reads and writes standard 
CP/M files. Versions are available for 
both the 8080 and Z80. The Z80 system 
uses the additional registers and instruc- 
tions of the Z80, and contains an 
assembler with Z80 mnemonics. The 
single-system price of $150 includes 
complete source code and a manual. 
Original equipment manufacturer (OEM) 
and resale licenses are available. For 
more information, contact The 
Stackworks, POB 1596, 321 E Kirkwood 
Ave, Bloomington IN 47402, (812) 
336-1600. 
Circle 531 on inquiry card. 



Word Processor and 8810 System from PolyMorphic 



Wordmaster II is a menu-driven word 
processor. The program enables users to 
create, edit, format, and print 
documents. It is designed for PolyMor- 
phic Systems 8810 or 8813 computers. 
The program can print with two-color rib- 
bons, print in boldface, print 
superscripts, subscripts, and multiple- 
line headers and footers. Repetitive 
spelling, phrase, or numerical errors can 
be easily changed. The System 8810 
with Wordmaster II is available for 
under $9000, including the NEC Spin- 



writer or comparable printer. Contact 
PolyMorphic Systems, 460 Ward Dr, 
Santa Barbara CA 93111. 
Circle 532 on inquiry card. 



256 August 1980 © BYTE Publications Inc 




WhafsNew? 



SYSTEMS 



Matrox Computer Systems 
MACS-10 

The MACS-10 microcomputer system 
combines Multibus-based hardware with 
the CP/M 2.0 disk operating system. 
The system is configured around the 
Z80A microprocessor and includes 48 K 
bytes of programmable memory and 
sockets for 8 K bytes of ROM (read- 
only memory) and EPROM (erasable 
programmable read-only memory). A 
2 K-byte monitor, a dual 8-inch double- 
density floppy-disk drive, a disk con- 
troller, and interfaces for a video ter- 
minal and line printer are also included. 
Other peripherals can be connected 
through additional ports at the rear of 
the chassis. The microprocessor and 
floppy-disk controller cards occupy two 
slots in the card cage, leaving five slots 
for systems expansion. If more slots are 
needed, up to three card cages can be 
stacked together for a maximum of nine- 
teen free card slots. Optional hardware 
includes a 128 K-byte programmable- 
memory card, and an alphanumeric and 
graphic video-display controllers. The 
price for the MACS-10 system is $5990. 
Details are available from Matrox Elec- 
tronic Systems Ltd, 5800 Andover Ave, 
T M R, Quebec H4T 1H4, Canada, 
(514) 735-1182. 

Circle 533 on inquiry card. 



The System 1000 Series 
from CSSN 

CSSN Inc has announced its System 
1000 family of microcomputers. This 
modular, bus-oriented line of systems is 
organized around the IEEE (Institute of 
Electrical and Electronic Engineers) S-100 
standard bus. The S/1000 includes a 
4 MHz Z80A microprocessor, 64 K 
bytes of programmable memory, an 
8-inch Winchester hard disk, a 
13.4-megabyte cartridge-tape data 
backup, a variety of I/O (input/output) 
devices and other peripherals, and ex- 
pansion capability to 16-bit processors. 
It is available in different configurations 
of operating systems and peripherals, 
and retails between $15,000 and 
$20,000. The S/1000 hard-disk cartridge 
backup combination can store 24 
megabytes. Operating systems for the 
series includes CP/M 2.0, MP/M, 
OASIS, and CSSN PDOS, a superset of 
CP/M 1.4. Languages such as BASIC, 
COBOL, FORTRAN, C, and Pascal, can 
be run on the systems. For further infor- 
mation, contact CSSN Inc, 120 Boylston 
St, 4th Fl, Boston MA 02116, (617) 
482-2343. 
Circle 534 on inquiry card. 




AmZ800 Single-Board Computer 



The Am96/4116 MonoBoard Com- 
puter uses the 16-bit processing power of 
the 4 MHz AmZ8002 microprocessor. 
Auxiliary support for the AmZ8002 in- 
cludes 32 K bytes of programmable 
memory, 8 K bytes of PROM (program- 
mable read-only memory) sockets, two 
serial and three parallel I/O (input/out- 
put) ports, and five programmable 
counter/timers. The two RS-232 serial 
ports transmit data from 50 to 9600 bps 
(bits per second). The parallel I/O ports 
break down into twenty-four lines or 
three 8-bit ports that can be programm- 
ed for input, output, or bidirectional 
operation. The computer can accept 
multiple interrupt channels from twenty- 



three independent sources in non- 
maskable, vectored, and nonvectored 
modes of operation. Eight interrupt 
channels are handled by a program- 
mable interrupt controller which 
allocates priorities, determines modes of 
operation and supports direct vectoring. 
The Am9513 System Timing Controller 
incorporates five independent 16-bit 
counters that can count up or down in 
binary or BCD (binary-coded decimal) 
at rates up to 7 MHz. The price for the 
Am96/4116 is $2145. Contact Advanced 
Micro Computers, 3340 Scott Blvd, 
Santa Clara CA 95051, (408) 988-7777. 

Circle 535 on inquiry card. 



System 800 from IPDI 

The System 800 can be expanded from 
64 K bytes to 2.04 megabytes of pro- 
grammable memory and from 11.2 to 
31.2 megabytes of disk storage on four 
drives. The system allows a combination 
of floppy and hard disks, as well as tape 
cartridge backup in the same system 
enclosure. IPDI's video-graphics card 
produces a display of up to 3000 



characters of over 256 user-definable 
characters and symbols on a 15-inch 
monitor. The video-display system 
features sixteen levels of gray or full 
color and is capable of driving over 
thirty-two displays. For more informa- 
tion, contact IPDI, 2584 Wyandotte, 
Mountain View CA 94043, (415) 
969-6086. 

Circle 536 on inquiry card. 



A Z8000 Board from 
Quasar Data Products 

This 16-bit Z8000 S-100 board con- 
forms to the proposed IEEE (Institute of 
Electrical and Electronic Engineers) stan- 
dards. The system can read and write 
8-bit, 16-bit or mixed 8- and 16-bit 
memories. The module also incorporates 
on-board, single-step circuitry hardware. 
The clock rate is 4 MHz. An 8080/Z80 
emulator enables users to employ most 
of the software that has been developed 
for the 8080/Z80 processors. The system 



also has provisions to plug an 8-bit 
microprocessor card in the same bus as 
the Z8000 module, allowing software to 
be developed on an 8-bit system and 
then transferred to and executed by the 
Z8000. Available software includes a 
cross assembler, text editor, word pro- 
cessing software, and a business 
package. The QDP-8100 is available 
from Quasar Data Products, 25151 
Mitchell Dr, North Olmsted OH 44070, 
(216) 779-9387, for $6395. 

Circle 537 on Inquiry card. 



August 1980 © BYTE Publications In 



257 



Circle 226 on inquiry card. 



WAMECO 

THE COMPLETE PC BOARD HOUSE 
EVERYTHING FOR THE S-100 BUSS 



■K FPB-1 FRONT PANEL BOARD FOR 8080A AND Z80 
SYSTEMS IMSAI COMPATIBLE. 
PCBD $54.95 KIT $165.00 

■* MEM-2 16K RAM 2114's. ADDRESSABLE IN 4K 
BOUNDARIES. 
PCBD ... $31.95 KIT (LESS RAMS) .... $80.95 

■* EPM-2 16/32K ROM USES 2716 OR 2708. ADDRESS- 
ABLE IN 4K BOUNDARIES. 
PCBD .... $31.95 KIT (LESS ROMS) .... $74.95 

■K CPU-1 8080A PROCESSOR BOARD WITH VECTOR 
INTERRUPT. 
PCBD $31.95 KIT $124.95 

■X- IOB-1 I/O BOARD. ONE SERIAL, TWO PARALLEL 
WITH CASSETTE. PCBD $31.95 

■X- FDC-1 FLOPPY DISC CONTROLLER BOARD USES 
1771. PCBD $44.95 



•X- QMB-12 13 SLOT MOTHER BOARD. 

PCBD $39.95 KIT $115.95 

■X- QMB-9 9 SLOT MOTHER BOARD. 

PCBD $34.95 KIT $89.95 

•X- PTB-1 POWER SUPPLY AND TERMINATOR BOARD. 
PCBD $29.95 KIT $49.95 

■3f RTC-1 REAL TIME CLOCK BOARD WITH TWO 
INTERRUPTS. 
PCBD $27.95 KIT $79.95 

■X- MEM-1 8K RAM, USES 2102's. 

PCBD .... $31.95 KIT (LESS RAM) $71.95 

•X- EPM-1 4K 170Z BOARD. 

PCBD .... $29.95 KIT (LESS ROM) .... $59.95 



FUTURE PRODUCTS: 80 CHARACTER VIDEO BOARD. 
Z-80 CPU BOARD WITH ROM, 8 PARALLEL PORT I/O BOARD. 

DEALER INQUIRIES INVITED, UNIVERSITY DISCOUNTS AVAILABLE 

AT YOUR LOCAL DEALER 

MOST PRODUCTS FOR IMMEDIATE SHIPMENT. NO 4-8 WEEK DELAYS REQUIRED FOR OTHERS. 



W777C 



inc. 



WAMECO, INC., P.O. BOX 877 • 455 PLAZA ALHAMBRA • EL GRANADA, CA 94018 • (415) 726-6378 



C/MOS IOIODE CLAMPED) 



4007 - 71 4030 - 

4009 - .45 4034 - 

4010 - .45 403S - 

4011 - .36 4040 - 

4012 - .35 4043 - 

4013 - .40 4043 - 

4014 - 1.20 4044 

4015 - 1.00 4040 - 
4010 - 4G 4049 - 

4017 - 1.06 4050 - 

4018 - 90 4061 - 

4019 - 45 4052 - 

4020 - 1.10 4063 - 

4021 - 1.10 4060 - 



402S - 35 4076 



74C20 
74C32 
74C42 
74C73 



'4CI92 - 
'4CS26 



14B8RS232 INTERFACE - 
MB9RS232 INTERFACE - 
25Q9TRI STATE STAT. SR - 
2522 STATIC SHIFT REG. - 
270BBKEPROM 1450 nil - 
TMS 3409 NC 80 BITS OYN.S.R. 
271S(TI1 3 VOLTAGES - 
2716-llnleri . 5V - I 

2tl4-)KSTAT.RAMM50rul - 
2532-4K - BEPftOM - I 

210211450 ns! - 
21L023l350m1 - 
MM5270 4KX1DYN. - 
MK4D0BP - 

2101-1254 i 4 STATIC - 
2111-1250 « 4 STATIC - 
21121256 * 4STATIC - 
MK40273 4K - 1 DYN. (200 ™t 
MK4090-11 4K . I DYN. RAM - 
4U6316KDYH.300NS - 
528021070 4K DYN. HAM - 
TMS4050L - 



TMS4T 



i-25-11 



250NS STATIC RAM - 
i B2S23 - 
i B2S115- 
I B2S123- 
I B2S129- 
i 82S12S- 

82S13I -- 

82S130 - 

AY51013UVART- 

TRI602B- 
i MC6B45- 

, MCM657IA7 - 9Chai.(jsi 
i MMM5321-TVSYMCGEN. 



B130 



2A6 



DATEL'S DAC-08BC - 8 bit DAC - $9.95 



8" DISKETTES - HARD SECTOR 

$1.75,10/$16.00 



4.000 MHz 
3.57 MHz 
5.000 MHz 
6.000 MHz 



8.000MHz 
10.000MHz 
18.000 MHz 
20.000 MHz 



RIBBON CABLE 
FLAT (COLOR CODED) 

130 WIRE 
26 cond. ■ .KWpof foot 
40 cond. ■ .75/per fool 
60 cond. - ,90/per tool 



RS232 
CONNECTORS 



DB25Pmale $3.25 

DB25S female ... $4.25 
HOODS $1.50 



FCS 8024 ■ 4 digit 
C.C. 8" display 
FND503C.C..5- 
FND510C.A..5" 
DL-704-.3" C.C. 



LED READOUTS 

S5.9S DL-707 CA. .3" 

S .85 DL747C.A. .6" 

S .85 HP3400.8-CA 

S ,B5 HP3405 .8" CC 



S .75 
S1.50 
$1.95 
51.95 



PRINTED CIRCUIT BOARD 



4" x 6" DOUBLE SIDED EPOXY BOARD 1 /16" 


thick 






5/S2.60 






EPOXY glass 


vector board 




1/16" thick with 1/10" spacing 4'/;" x &A" .. 


.. $1.95 


74S00 - 


.30 74S20 - .40 74S153 


- 1.10 


74S02 - 


.30 74S30 - .40 74S151 


- 1.25 


74S05 - 


.45 74S32 - .40 74S157 


- 1.25 


74 SOB - 


.40- 74S89 - 1.90 74S158 


- 1.25 


74S11 - 


.35 74S112 - .85 74S174 


- 1.40 


74S15 - 


.40 74S140 - 1.00 74S257 


- 1.50 



7 WATT LD-65 LASER DIODE IR $8.95 



25 watt Infra Red Pulse (SG 2006 equiv.) 
Laser Diode (Spec sheet included) 



MINIATURE MULTI-TURN TRIM POTS 
100, 5K, 10K, 20K, 250K. 1 Meg, $.75 each 




2N3820 P FET 

2N5457 N FET $ .45 

2N2646 UJT. 

ER 900 TRIGGER DIODES 4/$l .00 

2N 6028 PROG. UJT $ .65 

FP 100 PHOTO TRANS S .50 

RED, YELLOW OR GEEN LARGE LED's. 2" G/S1 .00 

RED/GREEN BIPOLAR LED's. 2" 5 .55 

MLED92 1 R LED $ .75 

MRD14B PHOTO DARL. XTOR $ .75 

TIL-118 OPTO-ISOLATOR $ .75 

IL-5 OPTO-ISOLATOR $ .BO 

1 WATT ZENERS: 3.3. 4.7. 5.1 . 5.6, 6.8, 8.2, 9.1 , 10, 
12. 1 5, 18, Of 22V 6'S1 .00 

TTL REED RELAY - SPST5V20mn S1.00 



SCR'S TRIACS 




1.5A 


SA 


35A 


110A 




PRV 


1A 


10A 


25A 


100 


.'.'. 


B0 


1 40 




lf/1 


.45 


.60 


1.55 


200 


70 


HO 


1 90 


9.00 


?oo 


.8-1 


1.30 


2.10 I 


400 


1.2ft 


■ .in 


? «l 


t? 00 


.;;:■:.. 


1.30 


1.90 


3.10 


GOO 




1.80 


3 60 


15.00 


BO ) 


2.00 


2.75 


4.30 1 



Minimum M.iilOukr 55 00 



SOLID STATE SALES 

P.O. BOX 74B 

SOMERVILLE, MASS. 02143 TEL. 16171547-7053 



WE SHIP OVER 95% 

OFOURORDERSTHE 

DAY WE RECEIVE THEM 



258 BYTE August 1980 



Circle 227 on inquiry card. 



TRS-80 
SERIAL I/O 

• Can input into basic 

• Can use LLIST and 
LPRINT to output, or 
output continuously • 
RS-232 compatible • 
Can be used with or 
without the expansion 
bus • On board switch 
selectable baud rates 
of 110,150,300,600, 
1200, 2400. parity or 
no parity odd or even, 
5 to 8 data bits, and 1 
or 2 stop bits. D.T.R. 
line • Requires +5, 
-12 VDC • Board only 
$1 9.95 Part No. 8010. 
with parts $59.95 Part 
No. 801 OA, assembled 
$79.95 Part No. 8010 
C. No connectors pro- 
vided, see below. 




EIA/F1S-23a con- 
nector Part No 
OB25PS6 0O.vwch 
9'. B conductor 
cable $10 95 Part 
No OB25P9 



3' ribbon cable 
tv.th attached con- 
nectors to litTRS- 
80 and our serial 
board S19 95 Part 
No 3CAB40 



COMPUCRUISE 




$1 29.95; with cruise con- 
trol $ 169.95 



PAPER TIGER 




Prints address labels, 
multicopy invoices and 
legal-size reports. Adjust 
the tractor width from 
1-3/4 to 9-1/2 inches. 
8 switch-selectable 
forms lengths. Print 6 
or 8 lines per inch. Add 
the software-selectable 
full dot plotting graphics 
option to print illustra- 
tions, block letters, 
charts, graphs. Part No. 

162 172 $899.95* with 
graphics option Part No. 

162173 $1099.95 



GAME PADDLES 
& SOUND 




Ws&+ 



Includes: 2 game pad- 
dles, interface, soft- 
ware, speaker, power 
supply, full documen- 
tation including: sche- 
matics, theory of 
operation, and user 
guide; plus 2 games on 
cassette (Pong and 
StarshipWar). $79.95 
Complete Part No. 
7922C 



DIGICOM DATA 
PRODUCTS INC. 

Series 312 
Acoustic Coupler 




300 BAUD Originate. 
Part No. AC3122, 
$219.95. 300 BAUD 
Answer, Part No. 
AC3122, $219.95. 
300 BAUD Answer/Or- 
iginate, PartNo.AC31 23, 
$229.95. 



IBEX 
LIGHT PEN 




Comes with Backgam- 
mon and Tic-Tac-Toe on 
tape with full documen- 
tation and program list- 
ing. Requires 9v. battery. 
Part No. IBEX $19.95 



SYSTEM 

EXPANSION 

from 

LNW Research 

• Serial RS232C/20 
mA I/O • Floppy con- 
troller • 32K bytes 
memory • Parallel print- 
er port • Dual cassette 
port • Real-time clock 

• Screen printer bus • 
Onboard power supply 

• Software compatible 

• Solder mask, silk 
screen. PC board and 
user manual. Part No. 
LNW80. $69.95. 



DISKETTES 



Yfeitoatim 



Box of 10, 5" $29.95, 
8" $39.95. 
Plastic box, holds 10 
diskettes, 5"- $4.50, 
8" -$6.50. 



16K RAMS 

For the Apple, 
TRS-BO or Pet $8 
each Part No. 4116/ 
2117. 



LEEDEX 
MONITOR 




12" Black and White- 
12 MHz Bandwidth 
• Handsome Plastic 
Case -$139.00 




AN S-1 00 bus Adapter— Motherboard for the 
TRS-80. Kit, Part No, HUH81 DLXK, $295.95. 
Assembeled, Part No. HUH81 DLXA. $375.95. 



NOW! 

A FULL SUPPORT SYSTEM 

FOR TRS-80 




• 32K of RAM • EPROM firmware • Disk 
control • Data acquisition • Parallel I/O • 
Serial I/O • Plug into GPA's Motherboard. 
GPA's quality design includes • 6-44 pin edge 
connectors • +5V. -5V, +12V, -12V external 
power supply required • Active termination. 
The Motherboard, Part No. GPA80. is only 
$149.95. 

TAKE ADVANTAGE OF 

GPA-EXPANSION CARDS 

FOR THE GPA80 

Memory cards: Now with Fortran compilers 
available for your TRS-80, additional expansion 
memory is a must! Card with sockets only, Part 
No. GPA801 ,$1 1 9.95. Card with 1 6K of 41 1 6 
Dynamic Ram, Part No. GPA802, $224.95. 
Card with 32K of 41 1 6 Dynamic Ram, Part No. 
GPA803, $329.95. All cards come equipped 
with sockets to accomodate 32 K of Ram. 
EPROM firmware card. Put those valuable 
subroutines in firmware. Don't waste time 
loading and unloading tapes and disks. For2708 
or 271 6 EPROMS. Part No. GPA806. $79.95. 
Serial I/O card. Here's what you've been 
asking for, a full serial terminal interface, with 
RS-232C or 20 mA. Current loop. Input/output 
capabilities. Part No. GPA807. $79.95. 
Parallel I/O Card. Control functions in the 
outside world, monitor and store real time 
events. Two parallel output ports. Dip switches 
select ports (0-254). Part No. GPA808, 
$79.95. 



FLOPPY DISK 
STORAGE BINDERS 




Three ring binder comes 
with ten transparent plas- 
tic sleeves which accom- 
modate either twenty, 
five-inch or ten, eight-inch 
floppy disks. Binder & 10 
holders, Part No. 81 OB— 
S9.95 • Extra holders. 
Part No. 81 0— 69C each. 



Three-ring binder with 
ten 5 1/4 inch jackets 
Part No. 51 OB— $9.95» 
Jackets only, fits stan- 
dard 3-ring binders, Part 
No. 510-691 each. 



DIGITAL 
CASSETTE 




5 min. each side. Box 
of 10 $9.95. Part No. 
C-5. 



TRENDCOM 
PRINTER 




TRENDCOM 200, Part 
No. TRCO200 $495.95. 
Interface for TRS-80. 
Part No. T80A $49.95, 
For Apple II, Part No. 
TRCALL. $75.95. For 
PET, NO. TRCP2, 
$79.95. For Scoccerer, 
TRCSR1 $45.95. 



SARGON: A Computer 
Chess Program 

Features the complete program that won the 
1978 West Coast Computer Faire Tourna- 
ment. Part No. 00603 —TRS-80 Level II; 
Part No. 00604 — Apple II (24K). $19.95 



SPINWRITER 
MODELS 5510 and 5520 




Features— EIA RS-232C/CCITT V.24 Inter- 
face Standard • 55 Characters Per Second 
Maximum Print Rate • Impeccable Print Quality 
(OCR Quality) • Microprocessor Electronics • 
High Resolution Plotting/Graphing • Lowest 
Operating Noise Level • Self-Test Printing • 
Operator Engineered Control Panel • Prints 
Original and up to Seven Copies • NEC Informa- 
tion Systems new Model 5510 Receive Only and 
Model 5520 Keyboard Send/Receive SPIN- 
WRITER terminals are microprocessor con- 
trolled serial, impact terminals designed for 
remote printing applications where impeccable 
print quality is required. Model 5510 RO, Part 
No. NECA30759 $2795.95 • Model 5520 
KSR, Part No. NECA30762 $3095.95 



Send for FREE Catalog.. .a big self addressed envelope with 80<P postage gets it fastest! 



TO OrdGf' Mention part no., description, and price. In USA shipping paid by us for orders accompanied by check or money 
1 order. We accept C.O.D. orders [U.S. only) or a VISA or Master Charge no., expiration date, signature and phone 
no., shipping charges will be added. CA residents add 6.5% for tax. Outside USA add 1 5°/o for air mail postage 
and handling. Payment must be in U.S. dollars. Dealer inquiries invited. Prices subject to change without notice. 



Order Line: (408) 448-0800 



ELECTRONIC SYSTEMS De P i B < R °- Box 2163a San Jose ' CA USA 95151 



Circle 217 on inquiry card. 



BYTE August 1980 259 



HEX ENCODED KEYBOARD 

Four onboard LEDs indi- 
cate the HEX code gen- 
erated for each key 
depression. The board 
requires a single +5 
volt supply. Board only 
$15.00 Part No. HEX-3, 
with parts $49.95 Part 
No. HEX- 3A. 44 pin 
edge connector $4.00 
Part No. 44P. 




T.V. 
TYPEWRITER 




• Stand alone TVT 

• 32 char/line, 16 
lines, modifications for 
64 char/line included 

• Parallel ASCII (TTL) 
input • Video output 

• 1 K on board memory 

• Output for computer 
controlled curser • 
Auto scroll • Non- 
destructive curser • 
Curser inputs: up, down, 
left, right, home, EOL, 
EOS • Scroll up, down 

• Requires +5 volts 
at 1.5 amps, and -1 2 
volts at 30 mA • All 
7400, TTL chips • 
Char. gen. 2513 • 
Upper case only • 
Board only $39.00 
Part No. 106, with 
parts $145.00 Part 
No. 106A 



44 BUS MOTHER 
BOARD 




Has provisions for ten 
44 pin (.156) connec- 
tors, spaced 3/4 of an 
inch apart. Pin 20 is 
connected to X, and 
22 is connected to Z 
for power and ground. 
All the other pins are 
connected in parallel. 
This board also has 
provisions for bypass 
capacitors. Board 
cost $15.00 Part No. 
102. Connectors 

$3.00 each Part No. 
44WR 



UART& 
BAUD RATE 
GENERATOR 




• Converts serial to 
parallel and parallel to 
serial • Low cost on 
board baud rate gener- 
ator • Baud rates: 
110, 150, 300, 600, 
1200, and 2400 • 
Low power drain +5 
volts and -12 volts 
required • TTL com- 
patible • All characters 
contain a start bit, 5 
to 8 data bits, 1 or 2 
stop bits, and either 
odd or even parity. • All 
connections go to a 44 
pin gold plated edge 
connector • Board only 
$12.00 Part No. 101, 
with parts $35.00 Part 
No. 101 A, 44 pin edge 
connector $4.00 Part 
No. 44P 



RS-232/20mA 
INTERFACE 




This board has two 
passive, opto-isola- 
ted circuits. One con- 
verts RS-232 to 
20mA, the other con- 
verts 20mA to RS- 
232. All connections 
go to a 10 pin edge 
connector. Requires 
+12 and -12 volts. 
Board only $9.95, 
part no. 7901, with 
parts $14.95 Part 
No. 7901A. 



ASCII TO CORRESPONDENCE 
CODE CONVERTER 

This bidirectional board is a direct replace- 
ment for the board inside the Trendata 1000 
terminal. The on board connector provides 
RS-232 serial in and out. Sold only as an 
assembled and tested unit for $249.95. 
Part No. TA1000C 



ASCII KEYBOARD 

53 Keys popular ASR-33 format • Rugged 
G-10 PC. Board • Tri-mode MOS encoding 
• Two-Key Rollover • MOS/DTL/TTL Compat- 
ible • Upper Case lockout • Data and Strobe 
inversion option • Three User Definable 
Keys • Low contact bounce • Selectable Par- 
ity • Custom Keycaps • George Risk Model 
753. Requires +5, -12 volts. $59.95 Kit. 



ASCII KEYBOARD 

TTL & DTL compatible • Full 67 key array 

• Full 128 character ASCII output • Positive 
logic with outputs resting low • Data Strobe 

• Five user-definable spare keys • Standard 
22 pin dual card edge connector • Requires 
+5VDC, 325 mA. Assembled & Tested. 
Cherry Pro Part No. P70-05AB. $1 19.95. 




A-to-D D-to-A CONVERTER 



•rtgftmliiwiljfe «j 



Analog to Digital, 
Digital to Analog 
Converter A-D con- 
version time 20us. 
D-A conversion 
5us. Uses include 
speech and music 
synthesizing and 
slow scan TV. Sin- 
gle power supply [5V1, B Bits wide, latched I/O, 
strobe lines. Part No. 79287K Complete Kit 
$49.95 • Part No. 79287A Assembled $69.95 



SOLID STATE SWITCH 




Your computer can control power 
(120VAC) to your printer, lights, 
and other 1 20VAC appliances up 
to720watts(6AMPSat1 20VAC). 
Input 3 to 15 VDC, 2-13 MA TTL 
compatible, isolation 1500V. Part No. 79000K 
1 Channel Kit $9.95 • Assm. $1 2.50 • Part No. 
79004K 4 Channel Kit $34.95 • Assm. $44.95. 




SUPER MODEM 

Orignate, RS-232 and 
20 mA compatable, Full 
duplex, and half duplex, 
direct connect or a- 
coustic coupled, on 
board power supply, car- 
rier detect light, DB25 plug , 300 BAUD, Type 
103 compatable frequencies, Bare board Part 
No. 2000, $1 9,95. Kit Part No. 20O0A, $99.95. 




T.V. INTERFACE 




• Converts video to 
AM modulated RF, 
Channels 2 or 3. So 
powerful almost no 
tuning is required. On 
board regulated power 
supply makes this ex- 
tremely stable. Rated 
very highly in Doctor 
Dobbs' Journal. Recom- 
mended by Apple • 
Power required is 12 
volts AC C.T., or +5 
volts DC • Board only 
$7.60 part No. 107, 
with parts $1 3.50 Part 
No. 107A 



SOROCIQ120 




Upper/lower case dis- 
play • Numeric keypad 
S. cursor keys • Pro- 
tected fields, Vs inten- 
sity display • RS 232 
interface S. aux. port. 
IQ120— $799.95 • 
IQ140 Detachable key- 
board— $1199.95 



RS-32/TTL 
INTERFACE 




• Converts TTL to RS- 
232, and converts RS- 
232 to TTL • Two se- 
parate circuits • Re- 
quires -12 and +12 
volts • All connections 
go to a 10 pin edge 
connector, kit $9.95 Part 
No. 232 A 1 Pin edge con - 
nector $3.00 part No. 
1DP. 



TAPE 
INTERFACE 




• Converts a low cost 
tape recorder to a 
digital recorder • Works 
up to 1200 baud •Dig- 
ital in and out are TTL- 
serial • Output of 
board connects to mic. 
in of recorder • Ear- 
phone of recorder con- 
nects to input on board 

• No coils • Requires 
+5 volts, low power 
drain • Board only 
$7.60 Part No. 111, 
with parts $29. 95Part 
No. 111A 



MODEM 




• Type 1 03 • Full or half 
duplex • Works up to 
300 baud • Originate 
or Answer • Serial TTL 
input and output • con- 
nect 8 n speaker and 
crystal mic. directly to 
board • Requires +5 
volts* Board only $7.60 
Part No. 1 09, with parts 
$29.95 Part No. 1 09A. 



COMPUCOLOR II 



a 



i 

With reg. keyboard 
MODS 8K $1449.95 
M0D4 16 K $1495.95 
M0D5 32K $1699.95 
Without disk drive sub- 
tract $450.00. Add-on 
drives, $495.00. With 
101 key option add 
$134.95. With 117 key 
option add $1 79.95. 



DC POWER SUPPLY 

• Board supplies a regulated +5 
volts at 3 amps., +1 2, -1 2, and -5 
volts at 1 amp. • Power required is 
8 volts AC at 3 amps., and 24 volts 
AC C.T. at 1.5 amps. • Board only fi 
$12.50 Part No. 60B5, with parts 
excluding transformers $42.50 
Part No. 6085A 




To Order: 



Send for FREE Catalog.. .a big self addressed envelope with 80$ postage gets it fastest! 



Mention part no., description, and price. In USA shipping paid by us for orders accompanied by check or money 
order. We accept C.O.D. orders (U.S. only) or a VISA or Master Charge no., expiration date, signature and phone 
no., shipping charges will be added. CA residents add B.5°/o for tax. Outside USA add 1 5% for air mail postage 
and handling. Payment must be in U.S. dollars. Dealer inquiries invited. Prices subject to change without notice. 



Order Line: (408) 448-0800 



ELECTRONIC SYSTEMS De Pt- B < R0 - Box21638, SanJose,CA USA 95151 



260 BYTE August 1980 



Circle 217 on inquiry card. 




16K$975.95, Extra 18K 
E.S. RAM installed 
$74.95, extra 32KE.S. 
RAM installed $1 48.95. 



APPLE II HOBBY/ 
PROTOTYPING CARD 

PartNo.7907$14.95 



APPLE II 
PARALLEL 
INTERFACE 




Interfaces printers, syn- 
thesizers keyboards, and 
JBE A-D D-A Converter 
& Switches. This inter- 
face has 4 I/O ports 
with handshaking logic, 
a-6522 VIA's and a 
74LS74 for timing. In- 
puts and outputs are 
TTL compatible. Part 
No. 79295K Complete 
Kit— $69.95 • Part No. 
79295A Assembled— 
$79.95 



REALTIME 

100,000 DAY 

CLOCK 

MI HARDWARE Dou- 
ble the utility of your 
S-10D bus computer 
with a real-time clock - 
that keeps time in 
100uS increments for 
over 273 years. Pro- 
gram events for the en- 
tire period with real time 
interrupts. ..without de- 
railing the system. Main- 
tain a log of computer 
usage, time and date 
transaction printouts, 
call up lists. On-board 
battery backup. 
MHPX004- $349.00 



16KEPROM 






Uses 2708 EPROMS, 
memory speed selec- 
tion provided, ad- 
dressable anywhere in 
65K of memory, can 
be shadowed in 4K in- 
crements. Board only 
$24.95 part no. 
7902, with parts less 
EPROMs$49.95part 
no. 7902A. 



PET COMPUTER 



With 1 6K & monitor— 
$895.00 • Dual Disk Drive 
—$1095.00 



OPTO-ISOLATED 

PARALLEL INPUT 

BOARD FOR 

APPLE II 




There are 8 inputs that 
can be driven from 
TTL logic or any 5 volt 
source. The circuit 
board can be plugged 
into any of the 8 sockets 
of your Apple II. It has 
a 16 pin socket for 
standard dip ribbon 
cable connection. 
Board only$1 5.00. Part 
No. 120, with parts 
$69.95. Part No. 120A. 



VIDEO TERMINAL 




Strir * 



16 lines, 64 columns- 
Upper and lower case 

• 5x7 dot matrix • Se- 
rial RS-232 in and out 
with TTL parallel 
keyboard input • On 
board baud rate 
generator 75, 110, 
150, 300, 600, & 
1200 jumper select- 
able • Memory 1024 
characters (7-21 L02) 

• Video processor chip 
SFF96364 by Necu- 
lonic • Control char- 
acters (CR, LF, -•, -, 
f , i, non destructive 
cursor, CS, home, CL 

• White characters on 
black background or 
vice-versa • With the 
addition of a key- 
board, video monitor 
or TV set with TV 
interface (part no. 
107A) and power 
supply this is a com- 
plete stand alone 
terminal • also S-100 
compatible • requires 
+ 16, S, -16 VDC at 
100mA, and8VDCat 
1A. Part No. 1000A 
$199.95 kit. 



qiB|DjQiqiqjqir-ij 



PARALLEL 

TRIAC OUTPUT 

BOARD FOR 

APPLE II 

This board has 8 triacs capable of switching 
1 1 volt 6 amp loads (660 watts per channel] or a 
total of 5280 watts. Board only $1 5.00 Part No. 
210. with parts $1 1 9.95 Part No. 21 OA 




apple ii-::- 

SERIAL I/O 
INTERFACE 



Baud rate is continuously adjustable from 
to 30,000 • Plugs into any peripheral 
connector • Low current drain. RS-232 input 
and output • On board switch selectable 5 to 
8 data bits, 1 or 2 stop bits, and parity or no 
parity either odd or even • Jumper selectable 
address • SOFTWARE • Input and Output 
routine from monitor or BASIC to teletype or 
other serial printer • Program for using an 
Apple II for a video or an intelligent terminal. 
Also can output in correspondence code to 
interface with some selectrics. • Also 
watches DTR • Board only $1 5.00 Part No. 
2, with parts $42.00 Part No. 2A, assembled 
$62.00 Part No. 2C 



8K EPROM PICEON 




• Programs 2708's address relocation of each 
4K of memory to any 4K boundary • Power on 
jump and reset jump option for "turnkey" 
systems and computers without a front panel 

• Program saver software in 1 2708 EPROM 
$25. Bare board $35 including custom coil, 
board with parts but no EPROMS $1 39, with 4 
EPROMS $1 79, with 8 EPROMS $219. 



WAMECO PRODUCTS 

With ELECTRONIC SYSTEMS parts 

FDC-1 FLOPPY CONTROLLER BOARD will 
drive shugart, pertek, remex 5" & 8" drives 
up to 8 drives, on board PROM with power 
boot up, will operate with CPM (not 
included). PCBD $42.95 

FPB-1 Front Panel. (Finally) IMSAI size hex 
displays. Byte or instruction single step. 
PCBD $42.95 

MEM-1A 8Kx8 fully buffered, S-100, uses 
2102 type RAMS. 
PCBD $24.95, $1 68 Kit 

QMB-1 S MOTHER BOARD, 1 3 slot, termi- 
nated, S-1 00 board only $34.95 

$89 95 Kit 

CPU-1 8080A Processor board S-1 00 with 

B level vector interrupt PCBD . . $25.95 

$89.95 Kit 

RTC-1 Realtime clock board. Two independ- 
ent interrupts. Software programmable. 
PCBD $25.95. $60.95 Kit 

EPM-2 2708/2716 16K/32K 

EPROM card PCBD $24.95 

$49.95 with parts less EPROMS 

QMB-9 MOTHER BOARD. Short Version of 

QMB-1 2. 9 Slots PCBD $30.95 

$67.95 Kit 

MEM-2 16Kx8 Fully Buffered 2114 Board 
PCBD $25.95, $269.95 Kit 

YOU MUST REFER TO THIS AD 
TO GET THESE PRICES. 



D.C. HAYES MICROMODEM 




Fully S-100 bus compatible including 16-bit 
machines and 4 MHz processors. • Two soft- 
ware selectable Baud rates— 300 Baud and a 
jumper selectable speed from 45 to 300 Baud. 
(110 standard). Supports originate and answer 
modes. • Direct-connect Microcoupler. This 
FCC-registered device provides direct access 
into your local telephone system, with none of 
the losses or distortions associated with acous- 
tic couplers and without a telephone company 
supplied data access arrangement. • Auto- 
Answer/ Auto-Call. The MICROMODEM 100 
can automatically answer the phone and receive 
input; it can also dial a number automatically. • 
Automatic Reset and Disconnect. • Software 
compatible with the D.C. Hayes Associates 
80-1 03A Data Communications Adapter. 
Micromodem-DCHA32625— $379.95 




TIDMA 



Tape Interface Direct Memory Access • Record 
and play programs without bootstrap loader (no 
prom) has FSK encoder/decoder for direct con- 
nections to low cost recorder at 1 200 baud rate, 
and direct connections for inputs and outputs to 
a digital recorder at any baud rate • S-100 bus 
compatible • Board only $35.00 Part No. 1 12, 
with parts $1 10.00 Part No. 1 12 A. 

SYSTEM MONITOR 

8080, 8085, or Z-80 System monitor for use 
with the TIDMA board. There is no need for 
the front panel. Complete with documentation 
$12.95. 



RS-232/TTY 
INTERFACE 



This board has two 
active circuits, one con- 
verts RS-232 to 20 mA, 
the other converts 20 
mA to RS-232. Re- 
quires +12 and -12 
volts. $9.95 Part Mo. 
600A Kit. 



SERIAL I/O 




Four Serial I/O RS-232 
ports. S-10D Bus. Soft- 
ware or jumper selectable 
baud rate (110, 300. 600, 
1200,2400,4800,9600, 
19.2K). on board Xtal baud 
rate generator, Address- 
ing, switch selectable, 
Parity or no parity (odd or 
even) switch selectable, 1 
or 2 stop bits, 5 to B 
bits/character. Board only 
$29.95, Part Nd. 7908. 
With parts (kit) $199.95, 
Part No. 7908A. 



S-100 BUS 
ACTIVE TERMINATOR 




Board only $14,95 Part No. 900, with parts 
$24.95 Part No. 900A 



Send for FREE Catalog...a big self addressed envelope with 804: postage gets it fastest! 



Tfl flrriPT" Mention part no., description, and price. In USA shipping paid by us for orders accompanied by check or money 
lu Ul UCI . orr j er y\/ e accept C.O.D. orders (U.S. only) or a VISA or Master Charge no., expiration date, signature and phone 



no., shipping charges will be added. CA residents add 6.5°/o for tax. Outside USA add 1 5°/o for air mail postage 
and handling. Payment must be in U.S. dollars. Dealer inquiries invited. Prices subject to change without notice. 



Order Line: (408) 448-0800 



ELECTRONIC SYSTEMS De P l - B - RQ Box 21638, San Jose, CA USA 95151 



Circle 217 on inquiry card. 



BYTE August 1980 261 



COMPUTER 
SYSTEMS 

J INC. 

15335 South Hawthorne Boulevard 
Lawndale, California 90260 
,„,,, (213) 970-0952 



TELEVIDEO 
SMART (CRT) 
TERMINAL 

• Reverse Video • Blinking/blank fields 

• Upper/lower case character • Protected fields 

• Non-glare screen • Underlining* 12 x 10 character 
resolution • Single stroke editing keys • Function 
keys • Blinking cursor • TTY keyboard • Numeric 
pad • 9 Baud rates (75-9600 Baud) • Self-test 

• Printer port 

912B $750100 

920B $850.00 

920C $900.00 

OPTION: 

2nd Page Memory $ 24.95 

Freight Charge $ 15.00 

Nationwide Field Service available from General 
Electric Instrumentation and Communication Equip- 
ment Service Shops. 

APPLE PRODUCTS 

MICRO-MODEM II $350.00 

SORRENTO CONTROLLER 

for 8" Apple Disk Drive $360.00 

INTROL X-10 SYSTEM 

(turns appliances on/off) $275.00 

MICRO-MUSIC (Software) $180.00 

AlO/Serial-Parallel Board A4T SSM $155.00 

INTEGER Firmware Card $179.00 

PARALLEL INTERFACE CARD $ 90.00 

VISICALC (Business Software 

Package) $124.95 

SUPER-MOD II (connects Apple to TV) ... $ 29.00 
ROM WRITER (Epromburner) 

Mountain Hardware $175.00 

PROGRAMMER AID #1 $ 50.00 

APPLE CLOCK $280.00 

SANYO 15" MONITOR $295.00 

SWITCHABLE 2 or 4 MHz 

THEQTZ+80REV1 

Z-80A CPU with Serial I/O Port 
This CPU can accommodate a 2708, 2716, or 2732 
EPROM in SHADOW mode, allowing you to use a 
full 64K of RAM. The MWRITE signal is generated 
automatically if you use the board without a front 
panel. There's also an independent on-board USART 
to control the RS232 serial port at baud rates from 
110 to 9600. 

CPU-Z+80K (KIT) $132.00 

CPU-Z+80AT (A&T) $189.00 

CPU-Z+BOBB (BARE BOARD) $ 33.00 

VERBATIM & MEMOREX 

Part No. Sectoring Pkg. ol 2 Box of 10 

OTMO 525 01 Soft Sector $ 8.85 $29.95 

QTMO 525 10 Hard 10 Sector $8.95 $29.95 

OTMO 525 16 Hard 16 Sector $8.85 $29.95 

QTF032 1000 Hard Sector $11.95 $34.95 

0TFO34 1000 Soft Sector $11.95 $34.95 

KASETTE/10 
LIBRARY 

Part No. 

CAS-10-8 Grey 8" Diskette Holder $4.50 

Black ... or3/$ia00 

Blue 

Beige 
CAS-10-5 Grey 5" Diskette Holder $4.25 

Black or 3/$1O00 

Blue 

Beige 

SPECIAL 
PACKAGE PRICE 

1 Male DB-25, 1 Female DB-25, 1 Cover 

RS-232 SET $6.50 



Look to QT for the 



APPLE 

SERIAL/PARALLEL 

INTERFACE 

Al/O Kit $125.00 

Al/O A&T $165.00 



16 X 64 VIDEO BD 

BY ITHACA AUDIO 

ASSEMBLED & TESTED 

• Full upper/lower case ASCII character set, 
numbers, symbols and Greek letters 

• 7 x 9 Dot matrix in 8 x 10 field 

• Selectable display modes, normal & reverse video, 
blinking characters 

• Memory addressable to any 1K page 

• Software driver simulates TTY, provides full cursor 
control, scrolling & paging 

AST PRICE ONLY $139.96 



IN STOCK 

All our advertised items 
are in stock and available 
for immediate delivery! 



DON SMITH 

Don brings to QT the 
same high level of 
personal service which he 
offered as sole owner of 
Jade Computer before he 
left in February of 1979. 



DISK DRIVE SYSTEMS 

S-100 

MS-800-1 (Drive with case, cables & 

power supply) $1095.00 

MS-800-2 (2 Drives with case, cables & 

power supply) $1595.00 

5 1 / 4 " DISK DRIVES 

MPI B-51 $295.00 

SHUGART SA400 $295.00 

8" DISK DRIVES 

SHUGART 8" 801R $45000 

REMEX RFD 4000 $635.00 

TEXTOOL 

ZIP* DIP II SOCKETS 

L.fef 4 

^ 1 ' nmn 

16 PIN ZIP* DIP II $ 5.50 

24 PIN ZIP* DIP II $ 7.50 

40 PIN ZIP* DIP II $10.25 

•ZERO INSERTION PRESSURE 



QT MEMORY EXPANSION KITS 

FOR 

TRS-80* APPLE • EXIDY 

4116 200 ns 
8 for $49.50 

2716 (5V - 450 ns) 
$18.00 

2716 (5&12V-450ns) 
$14.00 



PAPER TIGER 

• 132/80 Columns; 6 or 8 lines per inch 

• 1.75"-9.5" Adjustable Tractor and Friction Feed 

• Parallel and Serial Interface 

• 98 Character ASCII Set 

• 8 Software Selectable Character Sizes 

• 1 10, 300, 600 or 1200 Baud 

QT PRICES 

PT-132 $ 950.00 

PT-132G (Graphics & 2K Buffer) $1050.00 



STATIC RAM 
BOARDS 

SR-8K BARE BD (Ithaca Audio) 21L02 .... $ 19.00 
SR-16K BARE BD (Problem Solvers) 2114.$ 19.00 
SR-16K AST (Cal. Comp Sys) 

2114L 4MHz $269.95 

SR-32K KIT (Uses 21 1 4L) 4MHz $47500 

SR-32K A&T (Uses 2114L) 4MHz $500.00 



PARTS 

MICROPROCESSORS 



Z80 (2 MHz) $10.95 

Z80A (4 MHz) ... $12.95 

8502 $11.25 

6800 $12.50 

6802 $19.50 

8035 $20.00 

8080A $ 3.95 

8085A $20.00 

8086-4 $60.00 

8748-8 $70.00 

8080A SUPPORT 

8212 $ 3.50 

8214 $ 4.50 

8216 $ 2.95 

8224 $ 4.00 

8228 $ 6.00 

8238 $ 6.00 

8243 $ 5.00 

8251 $ 7.00 

8253 $19.00 

8253-5 $27.00 

8255 $ 6.25 

8257 $17.95 

8257-5 $19.00 

8259 $19.95 

8275 $69.95 

8279 $17.50 

8279-5 $1800 

8295 $16.50 

KEYBOARD CHIPS 

AY5-2376 $1175 

AY5-36O0 $1175 

BAUD RATE 
GENERATORS 

MC14411 $11.00 

1.8432 XTAL $ 4.95 

BR1941L $10.00 

DISC CONTROLLER 

1771B01 $24.95 

1791B01 $39.95 



EPROMS 

1702A $ 4.95 

2708 $ 6.75 

2516 $22.00 

2758 $27.00 

2532 $75.00 

2732 $75.00 

USRT 

S2350 $10.95 

MISCELLANEOUS 
OTHER COMPONENTS 

N8T20 $3.25 

N8T26 $ 2.50 

N8T97 $ 100 

N6T98 $ 2.00 

1488 $ 1.25 

1489 $ 1.25 

D3205 $ 3.00 

D3242 $1015 

D3245 $ 5.60 

P3404 $ 6.75 

TMS5501 $1900 

DM8131 $ 3.00 

CRT CONTROLLER 
MC6S45P $18.00 

STATIC RAMS 
2114L (450 ra) $5.25 M. 

100 M./W.50 •*. 

21141. (300 ra) $5.50 ••. 

100 M./S4.75 H. 

UARTS 

TR1602B $ 3.75 

CHARACTER 

GENERATORS 
2513 (Upper cm) $10.95 
2513 (Lower cue) $10.95 
2513 Upper (5 v) $ 9.75 
2513 Lower (5 v) $10.95 



EXPANDORAM I 

EXPANDABLE TO 64K USING 41 16 RAMS 

Interfaces with most popular S-100 boards 

Bank selectable; PHANTOM provision 

Draws only 5 watts fully populated 

Designed to work with Z-80, 8080. and 8085 systems 

No wait states required 

16K boundaries & protect via dip switches 

Kits come with sockets for full 64K 

Invisible refresh 

MEM-16K (16KKIT) $198.00 

MEM-16AT (16K A&T) $269.00 

MEM-32K (32K KIT) $260.00 

MEM-32AT (32K A&T) $329.00 

MEM-48K (48K KIT) $315.00 

MEM-4BAT (48K A&T) $379.00 

MEM-64K (64K KIT) $370.00 

MEM-64AT (64K A&T) $439.00 



EXPANDORAM H 

THE RANDOM ACCESS MEMORY 

S-100 Bus Compatible 

Up to 4Mhz Operation 

Expandable Memory from 16K to 256K 

Dip Switch Selectable Boundaries 

Uses 16K (4116) or 64K (4164) Memory Devices 

Page Mode Operation Allows up to 8 Memory 

Boards on Bus 
Operates with Z80 CPU's 
Phantom Output Disable 
Invisible Refresh (Synchronized with Wait States) 

MEMII-16K (KIT) .... $250.00 

MEMII-1SAT (A&T) W^» • • • J 30000 

MEMII-32K (KIT) \0 \ ..$325.00 

MEMII-32AT (A&T) / ^\ V *G%- . $375.00 
MEMII-48K (KIT) . . . \J. »Qv» .... $395.00 

MEMII-48AT (A&T) . . Ot^* $475.00 

MEMII-64K (KIT) V $475.00 

MEMII-64AT (A&T) $539.00 



Z-80 STARTER KIT 

COMPLETE Z-80 MICROCOMPUTER 

On-board keyboard, display, EPROM programmer. 

and cassette interface 

On-board S-1Q0 interface 

Wire-wrap area and room for 2 S-100 connectors 

Two 8-bit parallel I/O ports. 4-channel CTC. 5 

programmable breakpoints 

Examine and change memory. I/O ports, or register 

Z-80K (KIT) $310.00 

Z-80AT (A&T) $369.95 



SD SYSTEMS 



VERSAFLOPPYI 

SINGLE DENSITY DISK DRIVE CONTROLLER 
S-100 Bus Compatible 
IBM 3740 Compatible Soft-Sectored Format 
Operates with both Standard (8") and Mini (5V«") Drive 
Provides Control for Single or Double-Sided 

Operation 
Controls up to Four Drives Simultaneously 
Operates with SDOS or CP/M Disk Operation System 
Operates with Z80, 8080, and 8085 Central Processing 

Units 
Utilizes FD 1771B-1 Controller Device 
Control and Diagnostic Software Available in PROM 
Interrupt Operation Optional 

VF-IK (KIT) $235.00 

VF-IAT (A&T) $295.00 



VERSAFLOPPY H 

DOUBLE DENSITY DISK CONTROLLER 

Single or double density floppy disk controller 

985600 bytes on 8" double sided diskettes 

259840 bytes on double sided 5'/ 4 " diskettes 

S-100 bus (IEEE) standard compatible 

IBM 3740 format in single density 

8" and 5'/ 4 " drives controlled simultaneously 

Operates with Z-80. 8080, and 8085 CPU's 

Controls up to 4 drives 

Vectored interrupt operation optional 

VF-2K (KIT) $335.95 

VF-2AT (A&T) $385.95 



SBC-1 00/200 

OR 4 MHz SINGLE BOARD COMPUTER 

S-100 bus compatible Z-80 CPU 

1K of on-board RAM 

4 EPROM sockets accomodates 2708, 2716, or 2732 

One parallel and one serial I/O port 

4-channel counter timer chip (Z-80 CTC) 

Software programmable serial baud rates 

SBC-100K (2 MHz KIT) $280.00 

SBC-100AT (2 MHz A&T) $340.00 

SBC-200K (4 MHz KIT) $299.00 

SBC-200AT (4 MHz A&T) $359.00 



$25 REBATE 

on any SD Systems 

microcomputer board 

Offer expires 10-31-80 



VDB-8024 

VIDEO DISPLAY 
BOARD 

WITH ON-BOARD Z80 MICROPROCESSOR 

S-100 Bus Compatible 

Full 80 Characters by 24 Lines Display 

Characters Displayed by High Resolution 7 x 10 

Matrix 
Composite or TTL Video Output 
Keyboard Power and Interface 
Forward and Reverse Scrolling Capability 
Blinking, Underlining, Field Reverse, Field Protect 

and Combinations 
Full Cursor Control 
96 Upper and Lower Case Characters 
32 Special Character Set 
128 Additional User Programmable Characters 

(Optional) 
On-Board Z80 Microprocessor 
2K Bytes Independent On-Board RAM Memory 
Glitch-Free Display 

VDB-K (KIT) $365.00 

VDB-AT (A&T) $440.00 



PROM-100 



PROGRAMMING BOARD FOR PROM DEVELOPMENT 
S-100 Bus Compatible 
Programs the Following EPROMs: 

2708, Intel 2758, 2716, 2732 and Texas Instruments 

2516 
Dip Switch Selection of EPROM type 
25 VDC Programming Pulse Generated On Board 
Maximum Programming Time: 16,384 Bits in 100 

Seconds 
Power Requirement: +8VDC at 300 ma; +16 VDC at 

100 ma; -16VDC at 60 ma 
TTL Compatible 
Software Provides for Reading of Object File from 

SDOS, CP/M or PROM and Programming into 

EPROM 
Program Verification 
Verification of Erasure 
Zero Insertion Force Socket 

PROM-100K (KIT) $175.95 

PROM-100AT (A&T) $235.00 



S-100 BARE BOARDS 

CB1A 8080 CPU $33.00 

VB2 I/O Mapped Video Interlace $33.00 

102 Parallel I/O Interlace $33.00 

104 2P+ 2S I/O Interface $33.00 

SB1 Music Synthesizer $40.00 

OB1 Vector Jump & Prototyping Board $29.95 

MB3 4K 1702 EPROM Board $30.00 

MB6B 8K Static RAM $27.00 

MB7 Low Power 16K Static RAM $30.00 

MB8A 16K 2708 EPROM Board $30.00 

T1 Terminator $26.00 

MTI 15 Slot Motherboard $40.00 

XB1 Extender Board $13.50 

S-100 KITS & ASSEMBLED BOARDS 

CB1A 8080 CPU 

Kit $149.95 

Assembled & Tested $199.95 



CB2 Z-80 CPU 

Kit 

Assembled & Tested 



$195.00 
. $275.00 



MB3 4K 1702 EPROM Board 

Kit - without EPROMS 

Assembled & Tested 



. $ 65.00 
$125.00 



MB6B 8K Static RAM 
450 ns RAM 

Kit 

Assembled & Tested . 



$139.95 
$199.95 



^SS7PRODUCTS 



MB7 Low Power 16K Static RAM 

Kit $325.00 

Assembled & Tested $375.00 

MB8A 16K 2708 EPROM Board 

Kit - without EPROMS $ 99.00 

Assembled & Tested $159.00 

MT1 15 Slot Motherboard 

Kit (with Connectors) $119.95 

Assembled & Tested $149.95 

OB1 Vector Jump & Prototyping Board 

Kit $ 55.00 

Assembled & Tested $ 85.00 

PB1 2708/2716 EPROM Programmer 

Kit with Textool sockets $134.95 

Assembled & Tested w/Textools sockets$1 74.95 

SB1 Music Synthesizer (4) 

Kit $199.00 

Assembled & Tested $279.00 

T1 Active Terminator 

Kit $ 34.00 

Assembled & Tested $ 64.00 

Upgrade Kit for 80x24 Display 

2 MHz $ 69.00 

4 MHz $ 89.00 



VB1B Memory Mapped Video Interface 
LIMITED SUPPLY — DISCONTINUED 

Kit 

Assembled & Tested 



BOARD 

$149.95 

$180.00 



VB2 I/O Mapped Video Interlace 

Kit $160.00 

Assembled & Tested $210.00 



VB3 80 Character Video Interface 
80x24 Display, 2 MHz 

Kit $324.95 

Assembled & Tested $399.95 



XB1 Extender Board 

Kit (with Connector) . 
Assembled & Tested . 



. $ 19.95 
. $ 29.95 



80x24 Display, 4 MHz 

Kit 

Assembled & Tested . . 



. $369.95 
. $439.00 



I02 Parallel I/O Interface 

Kit 

Assembled & Tested 



. $ 59.00 
. $ 89.00 



I04 2P + 2S I/O Interface 

Kit 

Assembled & Tested 



. $134.95 
. $199.95 



250 ns RAM 

Kit 

Assembled & Tested . 



. $179.95 
. $245.00 



COMPUTER 
SYSTEMS 
I I INC. 

I 15335 South Hawthorne Boulevard 
_J Lawndale, California 90260 
quick » timhy (213) 970-0952 



PLACE ORDERS TOLL FREE 

1-800-421-5150 
(CONTINENTAL U.S. ONLY) 

(EXCEPT CALIFORNIA) 



TERMS OF SALE: Cash, checks, money 
orders, credit cards accepted Also COD 
orders under S100 00 Minimum order S10 00 
California residents add 6% sales tax Mini- 
mum shipping and handling charge S2 50 
Prices subiect to change without notice 
International sales in American dollars only 



$2130.00 COMPUTER 
GET A JADE INFLATION 



JADE Saves You$1130 

4 MHz BOARD SET T&tpZ 

SBC-200 CPU with I/O $400.00 

Versafloppy II Dbl density controllr . $430.00 
ExpandoRAM II 64K RAM 4 MHz . $1300.00 

Total price $2130.00 

JADE KIT PRICE $1074.95 

Less SD Systems Rebate $75.00 

YOUR COST ONLY $999.95 

S-100 Boards 

THE BIG Z - Jade 

2 or 4 MHz switckable Z-80 CPU with serial I/O 

CPU-30201K Kit $145.00 

CPU-30201A A&T $199.00 

CPU-30200B Bare board $35.00 

SBC-100 - SD Systems 

2.5 MHz Z-80 CPU with serial & parallel I/O ports 

CPC-30100K Kit $257.50 

CPC-30100A A&T $325.00 

SBC-200 - SD Systems 

4 MHz Z-80 CPU with serial & parallel I/O ports 

CPC-30200K Kit $399.95 

CPC-30200A A&T $475.00 

CB2 - S.S.M. 

2 or 4 MHz switchahle Z-80 CPU with RAM. ROM. & I/O 

CPU-30300K Kit $185.00 

CPC-30300A A&T $249.95 

ExpandoRAM I - SD Systems 

2. a MHz RAM board expandable from 16K to 64K 

MEM-16130K 16Kkit $189.00 

MEM-16130A I6KA&T $249.00 

MEM-32131K 32K kit $234.00 

MEM-32131A 32K A&T $294.00 

MEM-48132K 48K kit $279.00 

MEM-48132A 48K A & T $339.00 

MEM-64133K 64K kit $324.00 

MEM-64133A 64K A & T $384.00 

ExpandoRAM II - SD Systems 

4 MHz RAM board expandable from 16K to 256K 

MEM-16630A 16K kit $249.95 

MEM-16630A 16K A&T $299.95 

MEM-32631K 32K kit $309.95 

MEM-32631A 32K A&T $359.95 

MEM-48632K 48K kit $369.95 

MEM-48631A 48K A&T $409.95 

MEM-64633K 64 K kit $429.95 

MEM-64633A 64K A&T $479.95 

32K STATIC RAM - Jade 

MHz expandable static RAM board uses 21 14L's 



2 or 4 
MEM 
MEM 
MEM 
MEM 
MEM 
MEM 
MEM 
MEM 



16150K 
16150A 
-16151K 
16151A 
32150K 
32 150 A 
32151K 
32151A 



16K 2 MHz kit 
16K2MHzA& T 
16K 4 MHz kit ... 
16K4MHzA& T 
32K2MHzkit ... 
32K 2 MHz A&T 
32K 4 MHz kit . . . 
32K 4 MHz A&T 



$249.95 
$299.95 
$259.95 
$309.95 
$399.95 
$449.95 
$409.95 
$459.95 



16K STATIC RAM - Cal Comp Sys 

2 or -I MHz I6K static RAM - a real memory bargain 

MEM-16160K 16K 2 MHz kit $249.95 

MEM-16160A 16K2MHzA&T ... $279.00 

MEM-16162K 16K 4 MHz kit $279.95 

MEM-16162A 16K 4 MHz A&T... $309.00 
MEM-16160B Bare board $29.95 

Call for your free 1 980 catalog 



DOUBLE-D - Jade 

Double density controller with the inside track 

IOD-1200K Kit $299.95 

IOD-1200A 8" A&T $389.95 

IOD-1205A 5>A" A & T $389.95 

IOD-1200B Bare board $65.00' 

VERSAFLOPPY I - SD Systems 

Versatile floppy dish controller for 8" or 5'A" 

IOD-1150K Kit $219.95 

IOD-1150A A&T $269.95 

VERSAFLOPPY II - SD Systems 

New double density controller for both 8" & 5'/>" 

IOD-1160K Kit $309.95 

IOD-1160A A&T $369.95 

1/0-4 - S.S.M. 

2 serial I/O ports plus 2 parallel I/O ports 

IOI-1010K Kit $129.95 

IOI-1010A A&T $189.95 

IOI-1010B Bare board $29.95 

PB-1 - S.S.M. 

2708. 2716 EPROM board with built-in programmer 

MEM-99510K Kit $119.95 

MEM-99510A A & T $169.95 

PROM-100 - SD Systems 

2708. 2716. 2732. 27S8. & 2516 EPROM programmer 

MEM-99520K Kit $175.00 

MEM-99520A A&T $225.00 

32K BYTESAVER - Cromemco 

32K EPROM board with on-board 2716 programmer 
MEM-32550A A&T $295.00 

100K DAY CLOCK - Mtn Hardware 

Crystal controlled S-100 clock with NiCad bachup 
IOK-1400A A&T $329.95 

SB1 - S.S.M. 

15 Hz to 25K Hz music synthesizer for S-100 

IOS-1005K Kit $189.95 

IOS-1005A A&T $269.95 

TB-4 - Mullen 

Extremely versatile extender board with logic probe 

TSX-180K Kit $55.00 

TSX-180A A&T $75.00 

TERMINATOR & EXTENDER - CCS. 

Can be used as both an S-100 extender and terminator 
TSX-150K Kit $39.95 

S-100 EXTENDER - Cal Comp Sys 

Puts problem boards within easy reach 
TSX-160A A&T $24.95 

VDB-8024 - SD Systems 

80 x 24 I/O mapped video board with keyboard I O 

IOV-1020K Kit $324.95 

IOV-1020A A&T $379.95 

VB3 - S.S.M. 

80 x 24 or 80 x 48 memory mapped with graphics 

IOV-1095K Kit, 4 MHz $339.95 

IOV-1095A A&T, 4 MHz $399.00 

IOV-1096K 80 x 48 upgrade, 4 MHz . $89.00 

VIDEO BOARD - Jade 

64 x 16 assembled & tested S-100 video hoard 

IOV-1050B Bare board $29.95 

IOV-1050A A&T sale price $99.95 

8K RAM BOARDS - Special Sale 

Uses 211JI2 RAM chips 
2 boards & manual for $30.00 

Call for your free 1 980 catalog 



Single Board Computer 

AIM-65 - Rockwell 

0502 computer with printer, display, & keyboard 

CPK-50165 IK AIM $374.95 

CPK-50465 4K AIM $449.95 

SFK-74600008E 8K BASIC ROM . . . $99.95 
SFK-64600004E 4K assembler ROM $84.95 

PSX-030A Power supply $59.95 

ENX-000002 Enclosure $49.95 

■IK AIM. 8K BASIC, power supply, & enclosure 

Special package price $599.00 

32K RAM - for AIM-65 

Dynamic memory board to expand your AIM-65 
MEM-99170A A & T Wl out RAM .. $275.00 

MEM-16170A A&Tw/16K $325.00 

MEM-32170A A & T w/32K $375.00 

MEM-99170B Bare board $49.00 

DISK CONTROLLER - for AIM-65 

Add 5'A" or 8" disk drives to your AIM-65 
IOD-3013A A&T $575.00 

VISIBLE MEMORY - for AIM-65 

Video board with 8K memory & graphics for AIM-65 
IOV-301 1 A A&T $239.95 

MEMORY-MATE - for AIM-65 

The master-mater with 48K RAM. 1 O. PROM. & music 
MEM-52301A A&Tw/16K $475.00 

Z-80 STARTER KIT - SD Systems 

Z-80 computer with RAM. ROM. I O. & keyboard 

CPS-30010K Kit $289.95 

CPS-30010A A & T $349.95 

Accessories for Apple 

16K MEMORY UPGRADE 

Add 16K of RAM to your TRS-80. Apple, or Exidy 

MEX-16100K TRS-80 kit $49.95 

MEX-16101K Apple kit $49.95 

MEX-16102K Exidy kit $49.95 

DISK DRIVE for APPLE 

5'/" dish drive with controller for your Apple 

MSM-12310C with controller $495.00 

MSM-123101 w/ out controller $425.00 

8" DRIVES for APPLE 

Controller, DOS, two 8" drives, cabinet, & cable 
Special package price $1475.00 

AIO - S.S.M. 

Parallel & serial interface for your Apple 

IOI-2050K Kit $115.00 

IOI-2050A A&T $155.00 

SUP'R'TERMINAL - M & R Assoc 

80 x 24 video display board for your Apple 
IOV-2100A A&T ' $359.00 

SUPERTALKER - Mtn Hardware 

Speech recognition synthesizer w speaker & mike 
IOS-2015A A&T $275.00 

Z-80 CARD for APPLE 

Z-80 CPU card with CP M for your Apple 
CPX-30800A A&T $345.00 

MICROMODEM - D.C. Hayes 

Auto answer dial modem card for Apple or S-100 

IOM-2010A Apple modem $349.95 

IOM-1100A S-100 modem $375.00 

SUP'R'MOD II - M & R Assoc 

Color or B & W TV interface recommended for Apple 
IOR-5050A A&T $29.95 



NOW ONLY 
FIGHTING KIT T 




JUST 

ADD 

SOLDER 



Printers 

BASE 2 - Impact Printer 

!.'12 cps, bi-directional, tractor feed, & graphics 
PRM-13100 $625.00 

DP-9500 - Anadex 

9 x 9 dot matrix, 176 column, 21)0 cps, & graphics 
PRM-10500 Standard DP-9500 ... . $1495.00 
PRM-10510 with graphics & 2K .. $1595.00 

LP-80 - Matchless 

9 x 7 matrix, 132 column, 125 cps, bi-directional 
PRM-37204 $775.00 

PAPER TIGER - Integral Data 

132 Column, parallel & serial, 150 cps, graphics 

PRM-33440 IDS-440 $950.00 

PRM-33441 IDS-440 w/ graphics . . $1050.00 

MIPLOT - Watanabe Instruments 

Intelligent graphics plotter uses 7 bit ASCII code 
PRP-10800 $1075.00 

SPINWRITER - NEC 

65 cps. bi-directional, letter quality with tractor 
PRD-55510 with 2K buffer ..'..... $2995.00 

Motherboards 

ISO-BUS - Jade 

Silent, simple, and on sale - a belter motherboard 
6 Slot (5V," x »") 

MBS-061B Bare board $19.95 

MBS-061K Kit $39.95 

MBS-061 A A&T $49.95 

12 Slot (!> i" x 8V') 

MBS-121B Bare board $29.95 

MBS-121K Kit $69.95 

MBS-121 A A&T $89.95 

18 Slot (14!4" x »") 

MBS-181B Bare board $49.95 

MBS-181K Kit $99.95 

MBS-181A A&T $139.95 



Mainframes 



MAINFRAME - Cal Comp Sys 

12 slot S-100 mainframe with 20 amp power supply 

ENC-1 12105 Kit $309.95 

ENC-1 12106 A&T $349.95 

DISK MAINFRAME - NNC 

Dual 8" drive cutouts with 8 slot motherboard 
ENS- 112320 with 30 amp p.s $699.95 



Video Monitors 

VIDEO 100 - Leedex 

12" II & W video monitor with 12 MHz bandwidth 
VDM-801210 $139.95 

VIDEO 100-80 - Leedex 

81 x 24 version of Video 100 with metal cabinet 
VDM-801230 $179.95 

B & W MONITOR - Sanyo 

High quality, high resolution video monitors 

VDM-700901 9" monitor $209.95 

VDM-701501 15" monitor $279.95 

13" COLOR MONITOR - Zenith 

The hi res color you've been promising yourself 
VDC-201301 $449.00 



Call for your free 1 980 catalog 



Disk Drives 

JADE DISK PACKAGE 

Double-D controller kit, two 8" double density 

disk drives, cabinet, power supply, & cables 

Special package price $1295.00 

DUAL 8" DRIVES - Lobo 

A pair of double density Shugarts in a cabinet 

MSF-12800R 2 single sided $995.00 

MSF-125202 2 double sided $1425.00 

DISKETTES - Jade 

Bargain prices on magnificent magnetic media 
fi'/i" single sided, single density, box of 10 

MMD-51 10103 Soft sector $27.95 

MMD-51 11003 10 sector $27.95 

MMD-5111603 16 sector $27.95 

5'/i" double sided, double density, box of 10 

MMD-5220103 Soft sector ...'. $39.95 

8" single sided, single density, box of 10 

MMD-8110103 Soft sector $33.95 

H" single sided, double density, box of 10 

MMD-8120103 Soft sector $55.95 

8" double sided, double density, box of 10 
MMD-8220103 Soft sector ... $57.95 

FLOPPY SAVERS - Tri-Star 

Protect your valuable software from spindle damage 

MMA-205 5'//" kit $13.95 

MMA-208 8" kit $15.95 

Software 

CP/M 2.2 - Digital Research 

Latest & most powerful release of CP/M 

SFC-52506000D Manual set $24.95 

SFC-52506000M 5'A" disk & manual $149.95 
SFC-52506000F 8" disk & manual $149.95 

MP/M - Digital Research 

Multi-user operating system for Z-80 computers 
SFC-52507000F 8" disk & manual $295.00 

PASCAL/MT - MetaTech 

.4 powerful language for CP/M systems 
SFC-73301001F 8" disk & manual ..$99.95 

SDOS - SD Systems 

DOS. CBASIC-2, Z-80 assembler/editor/linker 

SFX-55001000D Manual set $24.95 

SFX-55001002M 5'A" disks & man $149.95 
SFX-55001006F 8" disk & manual $149.95 

WORDSTAR - MicroPro Intl 

The finest word-processing package for CP/M 
SFC-13600100F 8" disk & manual $395.00 

VISICALC - Personal Software 

Visible business accounting calculator for Apple 
SFA-24101005M 5'A" disk & manual $145.00 

SINGLE DRIVE COPY - for Apple 

Make back-up disks with just a single Disk II 
SFA-51150010M 5'A" disk & manual $19.95 

SUPER-TEXT - Muse 

Professional word-preteessing package for Apple 
SFA-13800085M 5'A" disk ■& manual $99.95 

Modems 

NOVATION CAT 

300 baud, auto answer originate acoustic modem 
IOM-5200A Special sale price $149.00 

EPROM ERASER - L.S. Engineering 

UV eraser for up to 48 EPROUs 
XME-3200 A&T $39.95 

Circle 220 on inquiry card. 




MICROPROCESSORS 

Z-80 $10.95 

7.-80A $14.95 

(.502 SI 1.511 

68(111 SI I. '15 

6802 S17.95 

6809 $39.95 

8035 $24.00 

80.15-8 $24.00 

8080A S 6.95 

8085 SI5.95 

TMS9900.il.. S39.95 



PROMS 

2708 (450ns) $ 8.95 
271 6 (450ns) $29.96 

2716 (5v) . . .$29.95 
27.12 (5v) . . . $69.95 
2758(5v)... $29.95 

RAMS 

211.02(2 Mil/1 ... S 1.25 ~^HL\ '' 
211.02(4 Mil/) ... S 1.50 wP*lL 

21141.(2 Mil/) ... S 5.75 ^* AI 

21141. (4 Mil/) ...% 5.95 i i 

4116 S 8.95 

2147 (70ns) $ 39.95 

4164 (64K x I) $175.00 

5257(2 MM/) $ 6.75 

5257(4 Mil/) $ 7.25 

DEVICFS tV VV^VL 

8212.... $"4.95 ^X^\^^ 

8214.... S 4.65 NV- 

8216 S 2.95 

8224... $4.95 1 ARTS 

8224-4 . . $9.95 AY5-10I3A . . $5.25 

8226 S 3.85 A Y3-10I4A . . S8.25 

8228 S 4.95 TR 1 602B . . . $5.25 

8238.... S 4.95 TMS60I1 ... S5.95 

8243.... S 8.00 1M6403 59.00 

8250 $14.95 

8251 .... $ 6.50 

8253.... $13.95 BAUD RATE 

8255 .... $ 6.50 GENERATORS 

8257....SI9.95 MCT441I ..$12.95 

8259.... $17.95 CRYSTAL. S 4.95 

8275 $49.95 

8279 $15.95 

6800 
7.80SITPORT SI PPORT 

3881 (PIO) S 9.5(1 6821 P . S 5.95 

3881-4 6828P . SI 1.95 

(PIO-4 Mil/) .. $14.50 6834P . S12.95 

3882 (CTC! S 9.50 6840P . $18.75 

3882-4 6850P . S 4.80 

(CTC-4MH/) .. SI4.95 6852P . S 5.79 

3883 (SIO) S29.50 68751. . $ 7.40 

3884 (SIO) S49.50 68488P S25.00 



PLACE ORDERS 
TOLL FREE 

Inside California Continental U.S 

800-262-1710 800-421-5500 

1- or customer sen ice 
or technical inquiries call 213-973-7707 

Write for our FREE 1980 catalog 







COMPUTER PRODUCTS 

4901 W.Rosecrans. Hawthorne. CA 90250 

TERMS OF SALE: Cash, checks, credit cards 
money orders or from recognized institutions 
Purchase orders accepted. Minimum order $10. 00? 1 
California residents add b% sales tax. Minim:. u* 
shipping and handling charge $2.50. Prices ar' for 
U.S. and Canadian delivery only and are subjcM 
to change without notice. For export prices jnd 
information send for a JAPE INTERNATIONAL 
CATALOG. |= 

I L 




.< 



If 



CaI-Forim-a DiqiTAl 

Post Office Box 3097 B • Torrance, California 90503 




NEW 



from 
INTEGRAL DATA 



Paper Tteer 



**** All the features of the 440 and more **** 
The 460 uses a dot matrix character formation technique in which 
the placement of the dots overlap both horizontally and vertically 
to achieve a correspondence-quality printing. 

The printer's nine-wire print head uses staggered needle rows lo 
create the vertically overlapping dots. The head is driven bi- 
direciionally under microprocessor control by a stepper motor 
driven mechanism with logic-seeking look ahead capability. 
Standard " Two-K Byte" buffer allows the printer to accept the 
entire content of a 1 ,920-character CRT screen. Weight 27 lbs. 
suggested list price $1,295. Calif. Digital price 



$1,076 



■J) M«t ts 

t ' "" -h 



DB25 



•<s 



each 10+ 

-i male >2.5° 1?5 

W°\ female 3» 30s 

llood-2p 12S 98 

Ontronic 695 



|BCD Thu s« eel l?5 

Ten Position 
Mfg. by Digis witch 
1 7/8 "high 1/2" wide 



. 



Authorized Distributor 

Scotch' 

Data Products 



B 



Edge 

Connectors 




GOLD 
100 PIN 

IMSAI/ALTAIR 

Imsai solder .125x250 $2.95 3 * 7.50 

Imsai *,». 125 centers S4.95 3/113.00 

Altatr snldertail .140 row 15.95 3-415.0O 

SPECIALS 

22/44 Him eyelet. 156" $1.95 3 $5.00 

25/50 solder tab .156" $1.09 3 S2 00 

36/72 wide post w/w. 156 $1.95 3/45.00 



S-100 Mother Board 

Quiet 
Suss 




WESTERN UNION 

ENCLOSURE 




TELETYPE MODEL 43 



4320 KEYBOARD 

TTL AAA $ 950 

RS232. ...AAK 1050 

Friction . . . AAE 

183 Modem AAB 1575 




1100 shipping 



TET 



li jiroihn 



Shipping weight 8 lbs. 



$24.95 



FREE 



PLASTIC LIBRARY CASE 

with purchase of each box of 

Memoren mini-diskettes. »5 value. 




DISKETTES 



CKT TEH M I N .' 
S Ro|M. 2a tlm key pj 

:lllne H20 



NEC Spinwrl 
Toam* Instrui 
Centronics 7 



■-.iiKart SA801H H hsrd I 
ubo / Two Shucuri 1101 * 

3WEI- *.ippl> Jul .-IK-k-BU 

Qii.- Sh-.iK.iri Mill ' 



Lolio hard drive fur 1'ltSi.U IMS 

Loii o 40o-i .=> 1/4' ior ritsao JW 

Vista V-H0 for TlHaO Hutrk) IS* 
Corvus Systems li.trd drive 

APPLE COMPATIBLE I'HODUCTS 
Apple disk drive with control I i-r jflu 
Apple drive without etmirulli-r 405 
Apple Parallel litter fact- 178 

Ten Key Data Pad tor Apple llu 
Mountain Hardware Kijti.-it.ilk 21V 
Mount jlii / Inlt-.r X-1U for liSIl 138 



C:l1. tiiRiial CAL-B5 
TreiT.ar a DUG 
Scuttle Computer.! tiuilfi 
CodkMUl HOnS/BOlTi 
tthacB tot ersy stems 7-HUi 
MISCtl.i.AM '.i 
Cherry I* ru ASCI 1 Keybd 
Maxlswilcn IIL.\ Keviijar 
DV brascr lt-£ 



740-0 IBM soft format. 
740/2 Double side soft 
741-0 Double density 
743-0 Double/Double 
740-32 8" Hard sector 
744-(0)(J0)(16) 5 l/4"niini 
Library case for any above 
834 A Data Cassette 
D C 100 Mini C artridge 
DC 300 Data Cartridge 
920( ) Disk Cartridge 



10 Pak 
$39.00 

65. 00 

53.00 

70.00 

39.00 

39.00 
; Add $3.00 
5.50 

16.00 

20.00 

39. 90 



50+ I 
3. 50| 

6. 00 1 
4.90 
6. 60 
3. 50 
3. 50 



*^Sh 



MEMORY 



TRS-80S, 
APPLE II 

16k memory (8) 4116's 



ugart Associates 



SA800-R Floppy Disk Drive 

The most cost effective way to store data proc- 
essing information, when random recall is a 
prime factor. I'hc SA800 is fully compatible 
with the IBM 3740 format. Write protect cir- 
cuitry, low maintenance A- Shu gar t quality. 



Installation is simple. Anyone who has 
ever changed a spark plug should be able ■ 
to up-grade his microcomputer. 
How can California Digital offer these 
memory up-grade sets at 25% below our competition? 
Simple, we buy in volume, wholesale to dealers and 
sell the balance directly to owners of personal micro- 
systems. These 16K dynamic memory circuits are 
factory prime and unconditionally guaranteed for one 
full year. NOW, before you change your mind, pick 
up the telephone and order your up-grade memory 
from California Digital. Add $3 for TR.S80 jumpers. 




£449 so 



XEROX 800 

WORD PROCESSING 

KEYBOARD 

ASCII ENCODED 



□ATA INPUT 
TERMINAL 



STATIC 


1 


-31 


32 


-99 


100-5C 


21L02 450nS. 


1 


19 




99 


.95 


21L02 250nS. 


1 


49 


1 


39 


1. 25 


21 14 1Kx4 450 


5 


95 


5 


50 


5.25 


2114 1Kx4 300 


8 


95 


8 


50 


8.00 


4044 4Kxl 450 


5 


95 


3 


50 


5.25 


4044 4Kxl 250 


9 


95 


9 


50 


9.00 


4045 1Kx4 450 


8 


95 


8 


50 


8.00 


4045 1KX4 250 


9 


95 


9 


50 


9.00 


5257 Low pow. 


5 


95 


5 


50 


5. 00 



-999 
.90 



1K+ 



4.75 4.50 



4. 80 4. 60 



2716 EPROM 



*** THOUSANDS *** 
We haVe slashed price in an effort to 
reduce our over stocked inventory. 
These are Single Five Volt Eproms, 
manufactured by one of the Worlds 
largest producers of semiconductors. 
Please phone for volume pricing. 



CMC division ot th< 
iii was originally desieni 
o magnetic tape. 



i aluminium and finer,;! 
' aboard. Thin 
cli luud speak 
II me ujiorjinr 01 punning problr" - 

trrriTin.il. rUb a little Imagination, c 
JT .ui S-100 computer anil video display 
■ Honk well A1M-GS micro/ consput.tr. 
upply is avalliitilii for an adiiilniiial $2H 
idtliort. 



direct connect 

MODEM 

Universal Data 107 

Connects directly to the new modular phone 
jack. 1'ullv powered from your existing 
telephone line. No need to locate external 
AC power. Crystal control prevents fre- 
quency drift. Uirect connect feature elim- 
inates loss of information due to carbon 
compression that is associated witli acous- 
tic modems. Runs circles around those 
other "Domestic 





PORTABLE DATA ENTRY SYSTEM 












re originally designed Tor ciinin stort 
The operator enters the Inventory o 
mrj the unit price. After all pertinent data has been entered in 
the recorder, !he main warehouse is telephoned, the handset is placed in the acinislii 
coupler and all the recorded information is transmitted back to the master computer. 
With a little imagine! ion and one of these portable entry systems, you should be able 
to exchange programs and computer information with associates across the country. 
All units were removed Ironi service In working condition. Original cost 82,506, 
Each system conies complete with: 

•Hot-table Cassette Drive Unit »Five Gould "D" NiCada >DB25 Cable 

•Removable Entry Keyboard -Acoustical Coupler .Shoulder starp 

.villi I. hit Uisplay 'It.rt'.i .:-y l.'l;..r,\i- -lull Documcntatio 



The new BSR timer runs 
your home like clockwork. 
Turns on lamps and appli- 
ances while your away 
from home. 

Completely compatible 
with your existing sys- 
tem X-10 devices. 





BSR Timer $65.00 

Master Console 34.95 

Ultrasonic Controller 19.95 
Modules: Appliance, 
Lamp or Wall Switch 13.95 



VISA 



All merchandise sold by California Digital is premium grade. 
Shipping: l-'irst five pounds $2.00; each additional add $.40 

California residents add 6% sales tax. COD's discouraged. 
Open accounts extended to state supported educational institu- 
tions and companies with a "Strong IXin & Bradstrcet. " 
Warehouse: 15608 Ingle wood Blvd. Visitors by appointment* 



TOLL FREE ORDER LINE 

(800)421-5041 

TECHNICAL & CALIFORNIA 

213)679-9001 

Circle 221 on inquiry card. 



page 



DEAL#1 

Hobby Wire Wrap Starter Package 

BW2630 WW Tool $19.95 

BT30 #30 Bit 3.95 

BC1 Batteries & Charger 14.95 
* Kit #1 Wire Kit 9.95 

Regular Price $48.80 

$39 95 

"Kit #1 Contains 900 pes. of precut wire 
in asst. sizes. 

Choose from Red, Blue. White. Black. 
Green, Orange, Violet, Yellow, or assort- 
ment. 




DEAL #2 

Industrial Wire Wrap Starter Package 




BW928BF WW Tool $52,95 

BT30I #30 Bit a Sleeve. . 29.50 
BC1 Batteries & Charger 14.95 
'Kit #3 Wire Kit 32.95 

Regular Price .. , $130.35 



$119 



95 



•Kit #2 Contains 4000 pes. of precut 
wire in asst. sizes. 

Choose from Red, Blue, White, Black, 
Green, Orange, Violet, Yellow or assort- 
ment. 



* * BIG DEAL * * 

IC Sockets by the Tube 




RN HIGH RELIABILITY 
eliminates trouble. "Sidewipe" 
contacts make 100% greater 
surface contact with the wide, 
flat sides of your IC leads for 
positive electrical connection. 










SOLDER TAIL 

Low Profile Tin 
Closed Entry 
Design 



"Sockets sold at these 
prices by the tube only. 



1<P/pin 

(over 5 tubes) 

3/4<P/pin 
(over 100 tubes) 

See tube quantities above. 



ORDERING INFORMATION 

Orders under $25 include $2 handling 
All prepaid orders shipped UPS Ppd. 
Visa, MC & COD's charged shipping 
All prices good through cover date 
Most orders shipped next day. 



Limited to products Page Ditigal stocks. All discounts are off of list price. 
Call or write for list prices. 

10% off on all OK hobby products! 

10% off on all Bishop Graphics products! 

5% off on all Vector products! 



WIRE WRAP 
SOCKETS 




Size 


Quantity/Tube Price ea. 


Price/Tube 


08 pin 
14 


52 
30 


.39 
.46 


$20.28 
$13.80 


3-level Gold 




16 


26 


.50 


$13.00 


Closed Entry 
Design 




18 
20 
22 


23 

21 
18 


.68 
.85 
.42 


$15.64 
$17.85 
$16.56 


•Sockets sold at these 
prices by the tube only. 


24 
28 
40 


17 
15 
10 


.94 
1.23 
1.60 


$15.95 
$18.45 
$16.00 






Above 


prices include gold up 


to $800/oz. 



page 



135 E. Chestnut Street 5A, Monrovia, California 91016 Phone (213) 357-5005 



Circle 222 on inquiry card. 



BYTE August 1980 267 




Qume Datatrak 8 

Double sided floppy with NO HEADACHES. 
Although many think this an impossibility, 
seeing is believing, and this drive is really 
something! Shugart compatible, fully option- 
ed, reliable, and rapidly becoming the stand- 
ard in double-sided diskdom. 

$599. Two/$549. 



Siemens FDD 100-8D 

Single sided 8" floppy drive, the latest 

& greatest revision. Features double density 

plus much more. An extremely reliable 

drive $439 2/$409 

Hard sector option kit... $9.95 

Data separator option kit... $9.95 

The following 5%." mini-floppies share most 
features with their 8" cousins, so without 
further ado. . . 

Siemens FDD 100-5D $279. 

Qume Datatrak 5 (double sided). . . . 399. 

BASF Mini mini . 279. 

SA 400 . . .... ......... 299. 

All the above mini-floppies are fully SA400 
compatible. 

Manuals for all drives are $10, refundable against future purchase of 
drives. Also, all 8" drives can be ordered with 220 v/50 hz for world- 
wide use. 





Disk controllers 

Delta Products double density $349 

Micromation doubler 439 

Tarbell single density, A & T 225 

Tarbell single density, kit 184 

Tarbell double density, DMA 425 
Sorrento Valley 8" single density 

for Apple 375 



Electrolabs' 
Monthly Special!!! 

TELEVIDEO 912C $699 

TELEVIDEO920C 799 

Features typewriter keyboard, microprocessor 
controls. Upper/lower case, adjustable baud rates 
(75-9600 baud), special function keys, much 
much more. 

Second page memory option $29.00 



Hard 
Disk 




Accessories 



' M --'S 



Cable kits for 8" drives with 10' 50 cond. flat cable, 
power cable, and all connectors. Assembled if de- 
sired. One drive 27.50, two 33.95, three 38.95 
for mini floppies (34 cond): one 24,95, two, 29.95 

CP-206 Power-one power supply. Powers two drives 
more than adequately, top quality. 2.8A/24V, 
2.5A/5V,.5A/-5V $99. 

mini-floppy power supply $79 



CM HB 10 MBY fully REMOVEABLE cartridge 
drive. Complete with controller, personality card, 
media, power supply, cabling, connectors and 
documentation. Highlighted by stylish & modern 
cabinetry. $6995. 

Shugart SA4008 20MB Y fixed disk sy stem. S-1 00, 
includes controller, power supply, and all that is 
necessary to run $6995. 



Data Display Monitors 

used 12" Sylvania monitors. Composite 
video, 12 MHz, 120 VAC. with new P-39 or 
P-4 tube, $79, used tube $59, OEM style 
(without case), subtract $12. U-fix model, 
10/$300. 

4116 dynamic ram, 16K Bonanza!! 

Set of 8, 16K, for Apple, TRS-80, Exidy, Heath & more. 200 Ns., 
prime parts, at the unheard of $49/8. 

Large discounts available for quantity & dealers (500 & up). Offer 
limited while supply lasts, as these will vanish quickly!!! 



Media 



Electrolabs 

POB 4436, Stanford, CA 94305 

415-321-5601 800-227-8266 

Telex: 345567 (Electrolab Pla) 
Visa MC Am. Exp. 





PRAGMATIX 1 



Incredible!.' — Two 8" Shugart compatible single sided floppy 
disk drives (double density), CP-206 power supply, in hand- 
some color coordinated cabinet, with full cabling, connectors, 
and documentation, plus one box diskettes!!! All for an un- 
precedented $1295. Up to one MBY of storage. 

with Qume Datatrak 8" double-sided drive $1695 




8" ...$39.99 SS/SD 
8" ...$49.00 SS/DD 
8" ...$55.00 DS/SD 
8" ...$59.00 DS/DD 
5%" $34.95 SS 
5V $59.00 DS 
Verbatim, Memorex, Scotch, or 
equivalent name brand 
Special Introductory Offer!!! 
Wabash 8" diskettes $29.00 SS 
$39.00 DS 
Price is cheap, but they run 
like champs!!!! 

Diskette head cleaning kit for 5Vi" or 8" 
$28.75 includes everything for 1 drive 
for 1 year. Alignment Diskette for 
Floppy Drives $39.00 



ENCLOSURES 




Rackmount Mainframe MT-200. This gorgeous 
beast is so appealing that it can easily function 
also as stand-alone mainframe. Very modern 
styling with fully actively terminated S-1 00 bus. 

With two 8" single-sided disk drives. . . $1899. 
With two 8" double sided disk drives in place 
of single-sided variety. . $2499. 

Desktop Mainframe MT-100. Contemporary styling, a handsome cabinet 

coated with durable epoxy finish colors (blue, beige, off-white & silver). 

Easy to fit into an office environment. The proper way to start your 

system. 

Above plus two 8" single sided disk drives $1 599. 

Above with two 8" double sided disk drives in place of single-sided 
variety $21 99. 

$25 min. order. Calif, residents add 6% sales tax. Orders under $75, add 5% shipping 
and handling, over $75 add 2.5%. All pricing subject to change without notice. 



268 BYTE August 1980 



Circle 223 on inquiry card. 








Keyboard 
Special 2 !! 

Keytronics1660 $149.00 

Hard Plastic enclosure 49.00 
BOTH only $152.00 



Keyboard 
Special 1 !! 



CHERRY "PRO" Keyboard 
$119.00 

Streamlined Custom Enclosure 

34.95 

BOTH only $134.95 



Daisy Wheel Printers 




NEC Spinwriter 5510/2 $2899 
NEC Spinwriter 5520/2 call 
NEC Spinwriter 5530/2 for 




ESAT 200B 

BILINGUAL 80x24 
Communicating Terminal 

Scrolling, full cursor, bell, 8x8 matrix, 110- 
19,200 baud, Dual Front Applications. 
Arabic & Hebrew, Multilingual Data Entry 
Forms Drawing, Music, & Switchyards. 

Alone $279. 

with Cherry Pro keyboard & 

custom metal case $399. 



Qume S/5 



prices 



Disk Subsystem 

Matchmaker Technology 
TURNKEY DISK SUBSYSTEMS 




APPLE Single density disk controller. Expanded Apple DOS 

TRS-80 Single or double density. Expansion interface neces- 
sary. Space for 48K dynamic RAM on controller card 
RS232 port 
SORCERER . . Full RS-232 Interface. One S-100 slot for memory ex- 
pansion. Single or double density 
All above units come as follows: Complete, assembled and tested, with 
two 8" floppy disk drives (Apple available in one drive model). Includes 
all cabling, connectors and documentation in a stunning color coordina- 
ted cabinet with power supply. Ready to go, plug in and run!!! 

When ordering specify single or double sided drives 

Software available for above disk add-ons 

TRS-80 & Sorcerer operate on alt CP/M compatible software 



Sprint 5/45 RO 


$2699 


Sprint 5/55 RO 


2829 


Sprint 5/45 KSR 


3029 


Sprint 5/55 KSR 


3159 


Forms Tractor 


$210 


Pinfeed platen 


155 


paper guide 


30 


paper basket 


50 



Qume 
Sprint 3\45 

(requires self assembly) 
printer mechanism $1499 

power supply 349 

combination special 1699 

cases 200 

S-100 interface card 149 



Circle 223 on inquiry card. 



many print wheels, ribbons, & more available 



Electrolabs 

POB 4436, Stanford, CA 94305 

415-321-5601 800-227-8266 

Telex: 345567 (Electrolab Pla) 
Visa MC Am. Exp. 



Peripheral Sale!! 

Hiplot Plotter $875. 

Hipad Digitizer 715. 

IDS 440 Paper tiger 899. 

SD Expandoram 1 1 

(A81T, 64K) 560. 

Imsai 65K dynamic RAM III 399. 

DC Hayes Micromodem 100 . . 399. 
Super switcher power for 

hard disk & more 349. 

DC Hayes Micromodem 1 1 

(for apple) $344 
DC Hayes Micromodem 100 $349 




735 LOMA VERDE. HU.O ALTO. CA 94303 

Database Management Systems 

HDBS A hierarchical Database Manage- 
ment System featuring fixed length records, 
read/write protection at file level and one 
to many set relationships. 

Z-S0 Optimized 250.00 

8080 Optimized 325.00 

6502 Optimized 325.00 

MDBS A large computer DBMS with 
hierarchical and full network data struc- 
tures (CODASYL Oriented). Explicit 
representation of one to one, one to 
many, many to one and many to many 
sets. Routines are callable from BASIC, 
PASCAL' COBOL or Machine Language. 



2-80 Optimized 
8080 Optimized 
6502 Optimized 



750.00 
825.00 
825.00 



Communications 
BISYfJC-8073780 a full function ibm 

2780/3780 emulator that provides one of 
the most widely used communications 
protocols. 550.00 

BISYI\IC-80/HASP A full function Hasp 
Multi-leaving Workstation package. 800.00 

BISYNC-80/ASYNC An asynchronous 
communications package that uses the 
full error correcting BISYNC protocol. 

95.00 

BISYNC-80/3270 a full function ibm 

3275 or 3271/3277 terminal emulator 
that converts a "dumb" terminal into a 
very smart one. 550,00 



Multiple License Pricing 

- Upon Inquiry - 



•LSI-11, PDP-11 TM DEC, UNIX TM 
Western Electric, CP/M TM Digital Research 





LSI11 Z-80 8080 8085 6502 



PHONE: 415 493-8186 



High Level Languages 

8080, 8085, Z-80 (Under OS-1 or CP/M) 

BASIC 

Microsoft Compiler 395.00. 

Microsoft "BASIC 80" 350.00 

FORTRAN 

Microsoft "FORTRAN 80" 

(Includes MACRO 80) 500.00 

COBOL 

Microsoft "COBOL 80" 750.00 

"C" 

Whitesmith's "C" 600.00 

PL/1 

Digital Research's PL/1 500.00 

PASCAL 

M.T. Compiler 250.00 

Z-80 Optimized (Under OS-1 or CP/M) 

COBOL 

R-M Z-80 COBOL ANSI '74 750.00 
LSI-11*/PDP-11* Under RT-11 or RSTS 

COBOL - ANSI 74 Introducing: 
RJ-11 Compiler 1750.00 

Applications in COBOL '74 

Available in R-M COBOL, COBOL 80 
and RJ-11. (Source Included) 



General Ledger 
Accounts Receivable 
Accounts Payable 
Inventory Control 
Order Entry/Invoicing 
COMPLETE LEGAL 
COMPLETE DENTAL 

Why COBOL? 
It's portable (ANSI '74) i 



995.00 
995.00 
995.00 
995.00 
995.00 
4200.00 
4200.00 

t's universal! 



OPERATING SYSTEMS 
TM Z-80 Optimized 

0S-1 A breakthrough in microcomputer 

software from Electrolabs! UNIX*-like OS 
with virtual I/O, bank-select memory control 
to 16 MBY and optional memory protection! 
Totally compatible with all CP/M programs. 
You will be amazed at the difference! Ex- 
cellent brochure available. Includes editor, 
linker-loader, debugger, and one year update. 

249.00 



CP/M 

Manua 

CP/M 
ZILOG 

Only f 
Manua 


8080, 8085 & Z-80 

Version 2.2 
s only 

- MCZ Version 2.2. 

MCZ and PDS-8000 

rom Software Labs! 
s only 


150.00 
25.00 

Runs on 

systems. 
200.00 
35.00 


OUR CATALOGUE 

Software 
Supplies 
Media 

Storage Equipment 
Publications 
- Upon Request - 



Circle 283 on inquiry card. 



TO ORDER 

*Price of manuals applied against software 
purchase. 

By Mail: Send check or money order (or 
P.O. from rated or institutional customers). 

By Phone: Use Master Charge or Visa No. 

Important Note: Please specify complete 
system hardware and software configuration 
with each order. 



7400 



74LS00 



SNM00N 


19 


SN74123N 


.59 


74LS00N 


35 


74LS164N 


1.19 


SN7401N 


22 


SN74125N 


.39 


74LS01N 


28 


74LS165N 


.89 


SN7402N 


22 


SN74126N 


.44 


74LS02N 


28 


74LSI66N 


2.48 


SN7403N 


22 


SN74128N 


.59 


74LS03N 


28 


74LS168N 


1.89 


SN7404N 


22 


SN74132N 


69 


74LS04N 


39 


74LS169N 


1.89 


SN7405N 


23 


SN74136N 


95 


74LS05N 


28 


74L.S170N 


1.99 


SN7106N 


23 


SN74139N 


.95 


74LS08N 


39 


74LS173N 


.89 


SN7407N 


.23 


SN74141N 


.69 


74LS09N 


39 


74LS174N 


.99 


5N7408N 


.26 


SN74142N 


2.95 


74LS10N 


28 


74LS175N 


.99 


SN7409N 


.23 


SN74143N 


2.95 


74LS11N 


39 


74LS181N 


2.20 


SN7410N 


.22 


SN74144N 


2.95 


74LS12N 


39 


74LS190N 


1.15 


SN7411N 


.29 


SN74145N 


.62 


74LS13N 


47 


74LS191N 


1.15 


SN7412N 


.29 


SN74147N 


1.95 


74LS14N 1 


25 


74LS192N 


.96 


SN7413N 


.39 


SN74148N 


1.20 


74LS15N 


39 


74LS193N 


.98 


SN7414N 


.59 


SN74150N 


.99 


74LS20N 


26 


74LS194N 


1.15 


SN74I6N 


.29 


SN74151N 


.67 


74LS21N 


36 


74LS195N 


95 


SN74I7N 


.29 


SN74152N 


.67 


74LS22N 


38 


74LS196N 


.89 


SN7420N 


22 


SN74153N 


.67 


74LS26N 


39 


74LS197N 


.89 


SN7421N 


35 


SN74154N 


1.19 


74LS27N 


39 


74LS221N 


1.49 


SN7422N 


.29 


SN74155N 


.82 


74LS28N 


39 


74LS240N 


2.99 


SN7423N 


29 


SN74156N 


.89 


74LS30N 


26 


74LS241N 


2.49 


SN7425N 


.29 


SN74157N 


.69 


74LS32N 


39 


74LS242N 


2.29 


SN7426N 


29 


SN74158N 


165 


74LS37N 


79 


74LS243N 


2.29 


SN7427N 


29 


SN74160N 


.95 


74LS38N 


39 


74LS244N 


2.95 


SN7429N 


.45 


SN74161N 


.95 


74LS40N 


26 


74LS245N 


8.95 


SN7430N 


23 


SN74162N 


.89 


74LS42N 


79 


74LS247N 


1.10 


SN7432N 


.29 


SN74163N 


.87 


74LS47IM 


79 


74LS248N 


1.10 


SN7437N 


29 


SN74164N 


.97 


74LS48N 


79 


74LS249N 


1.69 


SN7438N 


29 


SN74165N 


.97 


74LS51N 


26 


74LS251N 


1.79 


SN7439N 


29 


SN74166N 


1.20 


74LS54N 


35 


74LS253N 


.96 


SN7440N 


24 


SN74167N 


1.95 


74LS55N 


35 


74LS257N 


.96 


SN7441N 


79 


SN74170N 


169 


74LS73N 


45 


74LS258N 


.98 


SN7442N 


57 


SN74172N 


5.95 


74LS74N 


59 


74LS259N 


2.95 


SN7443N 


.79 


SN74173N 


.79 


74LS75N 


68 


74LS260N 


.69 


SN7444N 


.79 


SN74174N 


.89 


74LS76N 


45 


74LS261N 


2.49 


SN7445N 


.79 


SN74175N 


.89 


74LS78N 


65 


74LS266N 


.59 


SN7446N 


79 


SN74176N 


.85 


74LS83AN 


99 


74LS273N 


1.75 


SN7447N 


.59 


SN74177N 


.85 


74LS85N 1 


19 


74LS275N 


4.40 


SN7448N 


.79 


SN74179N 


1.80 


74LS86N 


45 


74LS279N 


.59 


SN7450N 


.23 


SN74180N 


.75 


74LS90N 


75 


74LS283N 


1.10 


SN7451N 


.23 


SN74181N 


1.75 


74LS92N 


75 


74LS290N 


1.29 


SN7453N 


.23 


SN74182N 


.75 


74LS93N 


75 


74LS293N 


1.95 


SN7454N 


.23 


SN74184N 


1.95 


74LS95N 


8B 


74LS295N 


1.10 


SN7459N 


.29 


SN74185N 


1.95 


74LS96N 


98 


74LS296N 


1.29 


SN74G0N 


.23 


SN74186N 


9.95 


74LS107N 


45 


74LS324N 


1.75 


SN7470N 


.39 


SN74188N 


3.90 


74LS109N 


45 


74LS347N 


1.95 


SN7472N 


.34 


SN74190N 


1.15 


74LS112N 


49 


74LS348N 


1.95 


SN7473N 


.38 


SN74191N 


1.15 


74LS113N 


49 


74LS352N 


1.65 


SN7474N 


36 


SN74192N 


.85 


74LS114N 


55 


74LS353N 


1.65 


SN7475N 


.38 


SN74193N 


.85 


74LS122N 


55 


74LS363N 


1.49 


SN7476N 


-36 


SN74194N 


.85 


74LS123N 1 


19 


74LS365N 


.99 


SN7479N 


4-60 


SN74195N 


.85 


74LS124N 1 


35 


74LS366N 


.99 


SN7480N 


59 


SN74196N 


.85 


74LS125N 


BS 


74LS367N 


.99 


SN7481N 


1.10 


SN74197N 


.85 


74LS126N 


69 


74LS368N 


.99 


SUTAS2N 


1.10 


SN74196N 


1.39 


74LS132N 


79 


74LS373N 


2.75 


SN7483N 


.55 


SN74199N 


1.39 


74LS136N 


59 


74LS374N 


2.75 


SN7485N 


.65 


SN74221N 


1.39 


74LS138N 


89 


74LS375N 


.69 


SN74B6N 


.39 


SN74251N 


.95 


74LS139N 


89 


74LS377N 


1.95 


SN7489N 


1.75 


SN74273N 


1.05 


74LS145N 1 


25 


74LS385N 


1.95 


SN7490N 


39 


SN74279N 


.89 


74LS148N 1 


49 


74LS386N 


.65 


SN7491N 


.65 


SN74283N 


2.15 


74LS151N 


79 


74LS390N 


1.95 


SN7492N 


.52 


SN74284N 


3.90 


74LS153N 


79 


74LS393N 


195 


SN7493N 


49 


SN74285N 


3.90 


74LS154N 2 


49 


74LS395N 


1.70 


SN7494N 


.72 


SN74290N 


1.25 


74LS155N 1 


19 


74LS399N 


2.95 


SN7495N 


.65 


SN74298N 


.95 


74LS156N 


99 


74LS424N 


2.95 


SN7496N 


.72 


SN74365N 


.68 


74LS157N 


99 


74LS668N 


1.75 


SN7497N 


3.10 


SN74366N 


.68 


74LS158N 


75 


74LS670N 


2.29 


SN74100N 


.99 


SN74367N 


-79 


74LS160N 


98 


81LS95N 


1.99 


SN74107N 


.32 


SN74368N 


.79 


74LS161N 1 


15 


81LS96N 


1.99 


SN74I09N 


.53 


SN74390N 


1.90 


74LS162N 


98 


B1LS97N 


1.99 


SN74116N 


1.95 


SN74393N 


1.90 


74LS163N 


98 


81LS98N 


1.99 


3N74121N 


.29 


SN74490N 


1.90 










SN74122N 


.39 
k ■ J 


l^%4* 




Lll 


II 


EAI 


I 


c 


M 


IOS 




7BH05 5 


95 


LM1414N 


1.90 


CD4000 


.29 


CD4093 


.99 


78M06 1 


49 


LM1458CN/N .49 


CD4001 


.29 


CD4094 


2.95 


78M.G. 1 


49 


MC14Q8N 


1.49 


CD4002 


.29 


CD4098 


2.49 


LM105H 


99 


MC1489N 


1/49 


CD4006 


1.39 


CD4099 


2.25 


LM108AH 2 


95 


LM1496N 


.89 


C04007 


.29 


MCI 4408 


12.95 


LM300H 


79 


LM1556N 


1.50 


C0400S 


1.39 


MCI 4409 


12.95 


LM301CN/H 


35 


LM1800N 


.79 


CD4009 


59 


MC14410 


12.95 


LM304H 


98 


LM1820N 


.95 


CD4010 


.59 


MC14412 


12.95 


LM305H 


89 


LM1850N 


.95 


CD40I1 


29 


MC14415 


8.95 


LM306H 3 


25 


LM1889N 


395 


C04012 


29 


MC14419 


4.95 


LM307CN/H 


29 


LM2111N 


1.75 


CD4013 


.49 


CD4501 


-39 


LM308CN/H ' 


98 


LM2900N 


.99 


CD4014 


1.39 


CD4502 


1.65 


LM309K 1 


49 


LM2901N 


2.50 


CD4015 


1 39 


CD4503 


.69 


LM310CN 1 


25 


LM2917N 


2.95 


CD4016 


.59 


CD4505 


3.95 


LW311D/CN/H 


98 


CA3013T 


2.29 


CD4017 


1 19 


CD4506 


.75 


LM312H 1 


75 


CA3018T 


1.99 


C04018 


1.19 


CD4507 


.95 


LM317T 2 


75 


CA3021T 


3.49 


CD4019 


49 


CD4508 


3.95 


LM318CN/H 1 


49 


CA3023T 


2.99 


CD4020 


1.19 


CD4510 


1.39 


LM319N/H 1 


26 


CA3035T 


2.75 


CD4021 


1 49 


CD4511 


1.39 


LM320K-XX- 1 


49 


CA3039T 


1.49 


CD4022 


1.29 


CD4512 


1.39 


LM320T-XX* 1 


25 


CA3046T 


1.29 


CD4023 


.38 


CD4515 


3.95 


LM320H-XX- 1 


25 


LM3053N 


1.49 


CD4024 


.79 


CD4516 


1.69 


LM323K 4 


95 


CA3059N 


3.25 


CD4025 


38 


CD4518 


1.39 


LM324N 1 


25 


CA3060N 


3.25 


CD4027 


.79 


CD4520 


1.39 


LM339N 


95 


CA3062N 


4.95 


CD4028 


.99 


CD4555 


4.95 


LM340K-XX' 1 


49 


LM3065N 


1.49 


CD4029 


1.29 


CD4556 


.99 


LM340T-XX* 1 


25 


CA308ON 


1.29 


CD4030 


69 


CD4566 


2.25 


LM340H-XX* 1 


25 


CA3081N 


1.69 


CD4031 


3.25 


74C00 


.39 


LM344H 1 


95 


CA3082N 


1.69 


C04032 


2.15 


74C02 


.39 


LM348N 1 


85 


CA3083N 


1.99 


C04034 


3.25 


74C04 


39 


LM358CN 


98 


CA3086N 


1.29 


CD4035 


1 19 


74C08 


.49 


LM360N 1 


49 


CA3089N 


2.75 


CD4037 


1.95 


74C10 


.49 


LM372N 1 


95 


CA3096N 


2.49 


CD4040 


1 29 


74C14 


1.65 


LM376N 3 


75 


CA3097N 


1.99 


CD4041 


1.25 


74C20 


.39 


LM377N 3 


75 


CA3130T 


2.49 


CD4042 


.99 


74C30 


.39 


LM380CN/N 1 


25 


CA3140T 


2.49 


CD4043 


.99 


74C32 


.99 


LM381N 1 


79 


CA3146N 


2.49 


C04Q44 


.99 


74C42 


1.85 


LM383T 1 


95 


CA3160T 


1.49 


CD4046 


2.25 


74C4B 


2.39 


LM386N 1 


49 


CA3190N 


1.95 


CD4047 


1.25 


74C73 


.99 


LM387N 1 


49 


CA3401N 


.69 


CD4046 


69 


74C74 


.99 


LM390N 1 


95 


MC3423N 


1.49 


CD4049 


69 


74CS5 


2.49 


NE531WT 3 


76 


MC3460N 


3.95 


CD4050 


69 


74C89 


4.95 


NE555V 


39 


SG3524N 


3.95 


CD405I 


1.10 


74C90 


1.55 


NE556N 


98 


CA3600N 


3.50 


CO4052 


1.10 


74C93 


1.85 


NE561T 19 


95 


LM3900N 


.59 


CD4053 


1.10 


74C95 


1.85 


NE562B 7 


95 


LM3905N 


1.49 


CD4055 


3.95 


74C107 


1.19 


NE565N/H 1 


25 


LM3909N 


.98 


CD4056 


2.95 


74C151 


2.49 


NE566H/V 1 


75 


RC4131N 


2.95 


CD4059 


9.95 


74C154 


3.50 


NE567V/H 1 


50 


RC4 1 36N 


1.10 


CD4060 


1.39 


74C157 


2.10 


NE592N 2 


75 


RC4151N 


4.50 


CD4066 


89 


74C160 


2.39 


LM702H 2 


99 


RC4 1 94 


4.95 


CD4069 


.35 


74C1S1 


2.30 


LM709N/H 


29 


HC4195 


4.40 


CD4070 


.69 


74C163 


2.39 


LM710N/H 


98 


ULN2001 


1.25 


CD407 1 


.35 


74C164 


2.39 


LM711N/H 


39 


ULN2003 


1.50 


CD4072 


.35 


74C173 


2.59 


LM715N 1 


95 


SN75450N 


.59 


C04073 


35 


74C174 


2.75 


LM723N/H 


75 


SN75451N 


.49 


CD4075 


.35 


74C175 


2-75 


LM733N/H 


98 


SN75452N 


.49 


CD4076 


1.29 


74C192 


2.39 


LM739N 1 


15 


SN75453N 


.49 


CD4077 


.35 


74C193 


2.39 


LM741CN/H 


33 


SN75454N 


.49 


CD4078 


35 


74C195 


2.39 


LM741CN-14 


19 


SN75491N 


,89 


CD4081 


.35 


74C922 


7.95 


LM747N/H 


79 


SN75492N 


.89 


CD4082 


35 


74C923 


6.95 


LM748N/H 


39 


SN75493N 


.89 


CD(1085 


195 


MM80C95 


1.50 


LM760CN 2 


95 


SN75494N 


.89 


C040B9 


2.95 


MM80C97 


1.25 


LM1310N 1 


90 








RETAILSTORESOPEN MON-SAT 

1310 "B" E. Edinger STORE 674 El Camlno Real 



STORE 1310 "B" E. Edinger 
" I Santa Ana, CA 92705 

loms, Retail, Warehouse 



AEMVNCED 

COMPUTER 
PRODUCTS 



BECKMAIM 

Digital Multimeters 



'^N 



100 00 



;TBr/ 



Ssifjj 



a IK H 3 lfl ros auto* touts 7 twrt <m 
29 ranges p*s Q25S Vfc actuary 
Tte TECH 300 to aO 5^ Wc accuracy and ad me aDtw teituti 
but wUtuI Insia-Ohms™ eanrury fcfldfefl o tnc ID amp cm- 

TECH 300 Digital Mulfmetor S100 

TECH 310 Digila! MulnmeKH $130 

VC-201 Vinyl Carrying Case $10 

DC-202 Deluie Carrying Case $24 

HV-211 High Voltage Probe $35. 

RP-221 RP Probe $35. 

Cl-231 AC Currenl Clamp $42, 

DL-241 Deluie Tesi Lead K.I . $10. 

TL-242 Spare Tesi Leads $6. 




ACPAPPLE MUSIC MACHINE 

WITH 9 VOICES! 

• NEW Uses latest Stale M 0* Ait LSI Ttetmdogy • 
R«ines wty ere slot 13 9 mti • Usesinee AY3-8910S In 
pcofett nne vm«s (Ointr coranliiive mottls have onty 3 
vKe5l • irtU3es software • S^ntiaies three ALF Boards 

• Plays rusic generated fry me ALF Boan) • APPLE'" II 

3 Times More Powerful Than ALFI 

HT Hi! is 

>S!EMILED1KD TESTED tI69 95 



THE BONE FONE 




I 



X* 



. > 



4T& 



• SKIERS 

• JOGGERS 

• SKATERS 

• CYCLERS 
You must hear 
it and teel il 
to believe ill 

AM/ FM stereo 
surrounds and 
(ills your body 
with sound. 
No earplugs. 
You wear it! 



'65 



95 



FLOPPY DISK DRIVES 

MP! B51-5VV, 40 tracks 279.00 

Shugart SA400-5 1 /*" 35 lracks 295.00 

Shugari 800/80 1 R 8" 475.00 

Siemens Shugari Compatible Modal 

FDD-1 20-8D 429.00 

PERSCI Model 277 Dual 1195.00 

WANGO/SIEMENS 5'/." Drive 290.00 

MPI B52 5V Dual 395.00 

WANGO/SIEMENS 202 Dual 5'/4 M .... 395.00 
WANGO/SIEMENS 82 290.00 

MONITORS 

Sanyo 9" $169.95 

Sanyo 15" 279.00 

Leedex 12" 1 39.95 

Motorola 1 2", High Resolulion, 

22 MHz. OEM Model 

*M3000-340 219.00 

Zenith 1 3"Color Monitor. . . 499.00 

MGA 13" Color TV 349.00 

VAMP 1 9" Color Monitor. , . 575.00 
VAMP 1 5" Color Monitor. . . 449.00 



ESBCONTINENTAL SPECIALTIES 

Modtl 3001 Digital Capacitance Meter . . 275.00 
Model 333 Tn-Mode Comparator . 29500 

Modal LM-3 40-fchannel Logic Monitor 58500 
Modal LM-I Logic Monitor ..... 60.00 

Modal LM-2 Logic Monitor 147.00 

ModalZDOlSweepableFLinclionGenerator .. 1B6.00 
Mndol SDOI Universal Counter-Tinier ... 360.00 
Mndil GOO 1 650 MHz Frequency Counter 385.00 
MM-IDO 100 MHz Portable Frequency Counter 

149.00 

PS-500 500 MHz Decade Prescaler 70.00 

MM-50 50 MHz Handheld Frequency Counter 

77.00 

MAX-550 550 MHz Handheld Frequency Counter 

165.00 

Modot 4001 Pulse Generator 835.00 

Modi! DM Digital Pulser 8300 

Logic Probes 

Modot LP-I Digital Logic Probe 50.00 

Modoi LP-2 Economy Logic Probe .', 28.00 

Modo! LP-3 High Speed Logic Probe 77.00 

Modal LPK-1 Logic Probe Kit 21.95 

Logic Probe Accessories 21 

Modot LTC-1 , LTC-2 Logical Analysis Kits . . 220/250 




! Apple II. 16K 
or Apple II. Plus $990 



1 6K Apple Upgrade Kit $62.95 



Hi-Speed Senal I/O. . . 
Centronics Printer I/O. . 
Applesoft II Firmware . 

Apple Clock 

Introl X-10 System,. 
Introi X-10 Controller 
All Music Synthesizer. . 
16 Ch Analog Input.. 
2 Ch Analog Output 

13- Key Keypad 

Visi-Cat 



5169.00 DS65 Okk-SkIh ... 

. 199.95 Apple Graphics Tablet 

,. 189.00 D.C Hayes Modem II 

. 269.00 Disk II w/Conlroller 

. 269.95 Disk II 

179.95 Pascal Lang Sysiem 

.25995 Parallel Prime* Card 

. 249.95 Communications Card 

164.95 BusinessSoftwarePkg 

119.95 Corvus 10 Megabyte Drrve 

.125.00 



S34900 


Integer ROM Card 


Si 89 00 


72500 


Prolo Card . .. 


. 2195 


34995 


M & R Modulatoi 


2995 


57500 


Sanyo Cassette. . 


54 95 


47500 


16K Upgrade Kit 


62.95 


450 00 


Desktop Plan 


9800 


16500 


8" Floppy Controller 


35000 


18900 


Heuristics SpeeChlab 


. 1 79.00 


62500 


RompJus + 


. 16900 


rt 


Supertafcer . . 


27900 


462500 


Cashier 


25000 



v A ATARI 800 & 400 

Personal Computer System 

ATARI 800 $750.00 
ATARI 400 S449.O0 

ATARI 800 Includes: Computer Console, BASIC Lang. Cartridge. Education 
System Master Cartridge, BASIC Language Programming Manual, 800 Operator's 
Manual w/Notebook, Atari 410 Program Recorder, 8K RAM Module, Power 
Supply, TV Switch Box. 



Super Breakout™ 
Mush Comcoser 
Sur*r Bug" 1 
ComputK Cdess 



EIkMh intra Cuuoi h><tmi 
US Halory 
US GowT¥nerfl 
Supervisory Stdk 
Wold History (Westernl 
Base Sxtkty 
Comsetfig PrnMdures 
ftncWs or Aceountmrj 

Greai Classes (EngtsM 
Busmess Ccmnunicalions 
Base PsychOUrjy 
Eteiive Writing 
Aulo Mechanics 
Pmco-les ol Econoniics 



Base Ffccmaty 
Base iltftn 



3500 
35 00 
3500 



3500 
3500 
3S00 



Oriving Controlef Pair 
PaUle ConuUler Pair 
Joystick Conlroiler Pa> 




Texas Instruments 



99/4 PERSONAL COMPUTER 

ound and Graphics -and a 
ic- All Built In. 

$1099.00 



Superior Color, Music. Sound and Graphics -and a 
Powerful Extended Basic - All Built In. 

Tl 99/4 Console only 
available lor $698.90. 



fs commodore 
PET L0W S AS $775.00 

DISCOUNT PRICES 



Hioi-eK 

2O0M6KN 
2O01-l6KB(reg| 
2O0I-32KN 
2O01-32KB (regl 
2022 BO-CoI Pol M 



. 77500 2023 BD-Col Plain Paper Pnntn 69500 

97500 2040 Dual Mm O.sk Dnw 125000 

975O0 Pel io IEEE CM 3995 

12S00D IEEE to IEEE Cable 4995 

125000 C2N E-ierral Cassene Deck 9500 
79500 




Model 41 S1 54.95 
without * ' ^■ W5 ' 



cruise control 
An onboard navigational cwnpuiei for aulantfxles, trucks, and 
recrealjunal «liidas Features cruise control fuel manage- 
ment system. Dip computer, multrtunctiaied warn crystal 
time counter, tfus many other functions 



HOME BURGLAR ALARM 




• No installation 

• Protects a whole house 

• Turns on lights automatically 

• Powerful electric siren 

• Exit and entry delay 

• Battery back-up 



CRAIG LANGUAGE 

TRANSLATOR AND 

INFORMATION CENTER 

An instant translator 

of words and 

phrases Irom the 
world's major lan- 
guages plus a lour 
function calculator 
plus information 
center lor nutrition. 

bar and wine 
guide, etc. 

SPECIAL LOW PRICE a H4A ac 
LIMITED TIME ONLY $>1 ly.yO 
(UNTIL AUGUST 17) 
PLUS £20.00 REBATE FROM CRAIG 
CRAIG MODULES AVAILABLE FROM S24.95 




The thermostat that uses microprocessor 
technology Io save fuel and money. 



PROGRAMMABLE 
TEMPERATURE 

CONTROLLER 




ACP PRICE 

$69.95 



A fully automatic electronic thermo- 
stat. Easy to install and operate. 
Compare the cost: TPI's temperature 
controller is the lowest priced elec- 
tronic thermostat on the market. 



SINGLE BOARD COMPUTER SELECTION GUIDE 



BOARD 

KIM-1 
SYM-1 

Cromemco 
SD-SBC100 
AIM 65 
Cosmac Vip 



PROCESSOR 


ACP PRICE 


ENCLOSURE 


6502 


1 69.00 


Add 29.95 


6502 


239.00 


Add 39.95 


Z80 


409.00 


N/A 


Z80 


239.00 


N/A 


6502 


375.00 


Add 49.95 


1802 


199.00 


Inc. 



#2 Tustin, CA 92680 

Specializing In Systems 



P.O. Box 17329 Irvine, Calif. 92713 

Direct Order Lines: (714) 558-8813 

(800) 854-8230 or (800) 854-8241 



FOR INTERNATIONAL ORDERS: 
1401 E. Borchard (714)9530604 
SantaAna,CA92705 TWX: 91 0-595-1565 



270 BYTE Augusl 1980 



Circle 225 on inquiry card. 



v^Iaemunced 

t p>-computeh 
^xmoducts, 



k5V 



STATICA / RAM BOARDS 



« S-1 00 32K (uses 2114) k** \,wi' 

ASSEMBLED Kit l'/>." > - 

450ns. 499.00 450ns. 469.00 

250ns. 539.00 250ns. 499.00 

Bare Board 49.95 
Bare Board w/all pan's less mem. 99.95 



• S-100 16K (S-1 00 Compatible) 

• 2 MHz " MHz WOW! 

• Assembled & Tested 
2 MHz.. S250.0O 
4 MHz. .$265.00 

• LOGOS I 8K 



SUfi 



ASSEMBLED 

450ns 149.95 KIT 450ns 12595 

250ns 169.95 250ns 149.95 

Bare PC Board w/Data S21.95 

'Special Oiler" Buy I4| 8K 450ns Kits 51 17 00 



Th« VISTA V-80 

Disk Drive System £ ,^ c , 

■ ?3 L t -rrf slwao* c^iaoly titan Tw> flnv, 



THE VISTA V-200 FOR EXIDY 



Price Skirling as low as S1 199.00 

Sltfifji Dim tvmn 

ii.i CukIIt C m lit ■ film WH|I1 Pnu 

WOO [ -20 400 2 Dnw 25 lbs 1 199 00 

Single Head 

v?00 f-2? BOO 2 Dnw 35 lbs 1H900 

Dcul* MeM 

vaae-w soa 3Dnve, 3?ik 152400 

Sinjte Head 

Wild E<l! I? MEG 3 0nve, 32 lis 1999 00 
Cool* Head 




ATTENTION VIDEO HOBBYISTS!!! 

* BOX BUILDERS 

* USE AS REMOTE TUNER/TIMER 

* FULL SCHEMATICS AVAILABLE 

* FOfl ONLY $5.90! - FREE W/PURCHASE 

A Recenl Special Purchase Allows Us To Present The Following: 

NEW, UNUSED COMPONENTS 

From The RCA VDT-201 

Videocassette Recorder 

1 UHFrVHF Tuner SutHSsemaiy wiin al 1 knob: 

ana Video Demodulate 

2 KF Mntjlalo win Auto I Vdeo inputs 

Channel 3 or 4 Output 

3 DrrjIa'Ciock Module A V'PM Fluorescent 

ileada.', (Grtenl 

4 300 Orim lo 75 Ohm Ualchirg 



5 Compete Sel a 



I The Al 



S59.95 

S39.95 

S19.95 

S 2.19 

Subtalar S1 23.34 



$74.95 

Please Call For Volume Discounts 



LOW COST FLOPPY 
DISK SUBSYSTEM 

Shugarl 80 1 R Drives {?) VISTA Floppy 
Controller (S-100), Case, Power Supply 
S Cable. CP/M Disk Operating System 

Assembled & Tasted SI 499.00 

• CHECK OUR FLOPPY DISK PRICING! 
ON THIS PAGE 

SAVE S300.00 {$1799.00 Value} 




WATANABE MIPLOT 



Wucall* 05 mm built' 

.lid 4 OWjfWi ot IDUtl 

draw, alpha pnnnng dc 



Ih simple commands $11 95.00 j 




IMS STATIC RAM BOARDS 

250 ns. 450 ns. 

8K Static S209.00 S189.00 

16K Static S449.00 S399.00 

32K Static S729.00 S629.00 



ANADEX PRINTER NEW APPLE VERSION 

Model DP-8000 compact, impact, parallel or 
serial. Sprocket feed, 80 cols, 
84 lines/min., bi-directional. 

New only S875.00 

DP-8000AP (for Apple)$875.00 



„.iel SD SYSTEMS BOARDS 

S* TAKE 10% OFF! kit a 



SBC tOO Singlet Board Comi 

SBC 200 Single Board Compuler (■ 

ZBO Starter System 

VDB G024 Video Display Board 

Versa-Floppy II 

Expands PROM 

SDtOO Computer System W/64K 

SD200 Compuler System W/64K 



) S265.00 S 349.00 



299.00 
319.00 
335.00 
325.00 
115.00 



399.00 
449.00 
459.00 
429.00 
225.00 
6995.00 
799500 



9601 16 Stol Mother Board 175.00 

9602 Card Cage 75.00 

9603 8 Slot Mother Board 100.00. 

9604 Power Supply 275.00 

9605 DC Input Power Supply 325.00 
9610 Utility Proto Board 39.00 
961 1 Anlh. Prcc/Memory Module 495.00 
9612 Buttered Utility Proto Board 49.00 

9616 32K EPROM/RAM Module 250.00 

9617 EPROM Programming Head 250.00 
9620 16 Channel Parallel I/O Module 295.00 
9622 Serial-Parallel I/O Module 325.00 
9627 1 6K Sialic RAM Module 470ns 395.00 

9629 32K Static RAM 450ns 695.00 
9629A 32K Static RAM 200ns 895.00 

9630 Card E.tender 68.00 
9640 Multiple Programmable Timer 395.00 
9650 8 Channel Duplex Serial I/O Mod 395.00 
9655 Intelligent Tape Controller 550.00 
96103 32/32 I/O Module 275.00 
96702 Contact Closure Module 350.00 

UNPOPULATED BOARDS iAIso Available! 



APPLE/EXIDY/EXPANDO 



$54.95 TRS-80/APPLE $54.95 

MEMORY EXPANSION KITS, 

4116's, 16K(200/250 ns.) 

8 pes for $54.95 

w/instructions & jumpers 
Call For Volume Pricing 

* Special: TRS80 Schematic S 4.95 

* Expansion Interface Schematic . . S 4.95 

* Expansion Interlace Connector... 7.95 



EXPANDORAM II MEMORY KITS 

* Bank Selectable + Uses 41 16 200 ns. 

+ Write Protect lfVW * Power 8VDC. ±16VDC 

• Phantom w^ces * Up to 4 MHz 

Expando 64 Kit (4116) Assem. S Tested Add $50. 
16K $269.00 48K $435.00 

32K $349.00 64K $505.00 



HAZELTINE TERMINALS 

SALE $749.00 

Model 1400 $71900 Model! 500 . S108500 
Model 1410 $82500 ModeH510 .5124500 

Model 1420 S945 00 Modeh520 $1495 00 



U\^Eprortr^raser^^ 

" Model UVs-1 1 E $69.95 

Holds 4 EprorrTs at a time 
Backed by 45 years 
experience. 

Model S-52T. . . $265.00 
Prolessional Industrial Model 




EMAKO-20. . Reg. S777.00 $599.00 




UNBELIEVABLE!! 

1 25Caps. 60 Ipm -Vertical 
Formal Unit -96 Charac- 
ters - Upper/Lower Case - 
4.5" to 9.5" Adjustable 
- BO col/40 col double 
width - Full 96char. ASCII 



EMAKO-22 $799.00 

Prints a 1 32 col/line. Available with parallel or serial 
output at same price. 

MIKA20 $1280.00 

9x7, 125 cps 136 characters/line 
Full 15" width. Super for business applications 
requiring large IBM format paper. 



BASE II PRINTER 




• 72,80, 96, 120 
132Char/Lme 

• Sen-Test Switch 



REG. S649.00 



ACP PRICE $550.00 

i "M" Terminal Scnl.tn Buffer [ I ['20 Char.] $50.00 

i"S" Highspeed Papal Advance S Graphics 50.00 

iTTmetorFwd so.oo 



Z-80/Z-80A/8080 CPU BOARD 

+ On board 2708 * 2708 included (450ns.) 

• Power on jump * completely socketed 

• 2-80 Assembled and Tested $1 85.00 

• Z-80 Kit $129.95 

• Z-80 Bare PC Board $ 34.95 

• For 4MHz Speed Add 51 5.00 

8080A Kit $ 99.95 

8080A Assembled SI 49,95 

S-100 MOTHERBOARD SPECIAL 

8 slot expandable w/9 conn. 

reg S69.95 NOW S52.95 



SIEMEN'S FLOPPY 



SALE 

SIEMENS 
$429.00 

SHUGART 

801 R 
$475.00 



ACOUSTIC MODEM 

NOVATION CAT™ 

0-300 Baud 

Bell 103 

Answer, Originate $179.95 




DATA BOOKS • COMPUTER BOOKS 

1980 1C Muster 59.95 imel MCS 80 Manual 7.95 

NSCTTLDaln 3.95 Inlel MCS 40 Manual 4.95 

NSC Linear 4.95 AMD B080A Manual 5.95 

NSC Linear App Notes II 3.95 AMD Schotlfcy Databook.. 4.95 

NSCCMOS 395 AMI MOS/LSI Data 3.95 

NSCMomory 3 95 Gl MOS'LSI Data 4.95 

Intel Daiabook . . . .7.50 Hams Analog Databook.. .4.95 

Intel MCS 85 Manual . .7.50 Tl Linear Control Data 3.95 

SALE • OSBORNE BOOKS ■ SALE 

Inlro to Micros Vol TSfiO 7.75 

Inlro 10 Micros Vol I 8"SQ 7.75 

8080A Programming &SQ 7.75 

6800 Programming ETSQ 7.75 

Z80 Programming . d~5Q 7.75 

Vol. II Some Roal MiLiopuctissors */3 -iJt>" 3&SQ 27.50 

Vol. Ill Some Roal S. ;.■:»'! Devices wB.i>de' 29*0. 18.50 

Intro to Micros Vol III . 2*90.18.50 
SALE ■ DILITHIUM COMPUTER BOOKS • SALE 

Understanding Computers.. , *-9*. 7.95 

BOBOMicrocomputer Experiments TT9*. 11.95 

Beginning. BASIC n-96. 8.95 

Beginners Glossary & Guide 6*96. 5.95 

Peanul Butter & Jelly Guide to Compote's T-9fc 6.95 

8080 Machine Language Prog Mi' mm 3 "r-9i. 6.95 

Home Computers Vol. I Hard*a'e 7-96- 6.95 

Home Computers Vol, II Soflwa'C "r*96. 11,95 

Starship Simulator T-96- 6.95 



FIRST TO OFFER PRIME PRODUCTS TO THE HOBBYIST AT FAIR PRICES! 
1« Proven Quality Factory tested products only. 

2. Guaranteed Satisfaction 

3. Over $1,000,000.00 Inventory 
1980 CATALOG NOW AVAILABLE. 

Send $2.00 for your copy of the most complete catalog of computer products. 
A must for the serious computer user. 

MICROPROCESSORS 



Z80O1 16 bil 1o 8Mb.. $189.00 

ZBOO? 16 hilloR4K . 14900 

Z80 .10.75 

Z80A .... 1450 

F-81.3850) 1695 

2650 18 95 

CD1802 . .... 13 95 

8080A .... 8 50 

8080A4MH7 1995 

SALE 8085 1 9.95 

8008 1 - - 14.95 

3901 ,. 990 

2901A 14.95 

2903 inn Supersuce . 39 95 
TMS9900J:. 49 95 

CP1600 39.95 

6502 11.50 

6502A 16 95 

IM6100 . 29.95 

aaoo 11.75 

6800F3?0MH* 1995 

6802P 17,95 

B035 19.95 

8755 4995 

B748 .......... 69 95 

6809 -84.95 

80B6 . .68-95 

ADVANCED SUPPORT 

AM9511 Anlh, Processor ... 175.00 

95 1 2 Aritn Processor 1 75.00 

9513 Univ. Timing 79.95 

AM9517 DMA Controller 18.95 

AM95 1 9 Universal Interrupt ... 1 8.95 

Z-80 SUPPORT CHIPS 



Z80-PIO 
Z80A-PIO 

zao-cTc 

ZB0A-CTC 
Z80-OMA 



2 5 MHz 



B.75 



ZBOA-DMA 4 MH* 

Z80'SIO/0 26 Mill 

Z80ASIO/0 ■:0 :.■!'/ 

Z80SIO/1 2 5 MHi 

Z80A-SIO/1 4 MHi 
Z80-SIO/2 



4.0 MHz 12.95 

25MHr 875 

MHz ., 12 95 
2 5 MHz 39 95 

36 95 



33 40 
35 95 
39 40 
35.95 



STATIC RAMS 






1*34 


25-99 


100 


31L02 450ns 


1.3< 


1.25 


.99 


31L03 250ns. 


1.5! 


1.55 


1.15 


2111 




3.7£ 


3.65 


3.55 


2112-1 




;>,»* 


2.85 


2.65 


2101-1 




2.91 


2.7C 


2.55 


21 14L-250ns. 14045) 


8.9E 


7.50 


650 


2114L-450na. (4045) 


5.5C 


5.25 


4.75 


4044 250 ns. 


835 


7.50 


690 


4044 450na. 


h«r- 


5.95 


4.75 


EMM4200A 


9.75 




7.95 


EMM4402 


7 9^ 


7.25 


6.25 


EMM4B04 


12.51 


11.50 


9.95 


5101C-E 




7.95 


7.95 


7,25 


AMD9K 




10.95 


10.25 


9.25 


AMD9 130/31 




11.95 


10.25 


1101 




1.95 


1.75 


1.25 


P2l25/93425(45ns.) 


9.95 


8.35 


825 


6508 IH 


X 1 CMOS 


7.95 


7.95 


7.25 


6518 1C 


x 1 CMOS 


7.95 


7.95 


7.25 


74S189 64 bit Ram 


3.95 


3.25 


2.50 


2147 Loi 


w Power 4K Slat 


19.95 18 95 


16.95 




DYNAMIC RAMS 










Set oi 3 


416's 






S4.9S 


41 15 OK [16 P>n) 




























4096 4« 


. 1 (16 Pm) ,. 






395 






















5261 
5262 


\U 64K 


11C3 


1.95 


5370 


"ot RAMS 


6605 


7.95 


5290 


•2«$175.00 


6003 


1.50 




SOCKETS 


:■• Pins 


Lo-Pro Solde 


f Wire Wrap 3 Level 


rtall 








15 






45 


14 






36 


.59 




.20 




.38 


62 


18 


.24 




.59 


.84 


20 


.29 




.69 


99 


22 


.24 




.79 


1.10 


24 


.38 




.85 


1.20 


26 


.43 




1.10 


1.49 


36 


.58 




1.25 


1.69 


40 


.60 




1.40 


1 89 




ZERO INSERTION FORCE 


16Pin S5.50 24Pin S7.50 


40 Pin 


S10 25 



FLOPPY DISK I/O 



1771-01 8"& MinitloiWV 
uPd372 Nee Floppy 
1781 Dual Floppy ... 
1791-01 Dual Floppy 
uPd 765 Floppy 



2995 
3695 
49 95 



A/D CONVERTERS 



8703 8 bil TS . 

9400 Von to Fien Co 
8750 3V; Digil BCD 
140BL66bil. .. . 



. 13 50 
2200 
13.50 
7.25 
13.95 
.3.95 
.5 95 
.. 5.95 



LED READOUTS 



Z80-SIO/2 4 MHz .. .3940 

8060/8085 SUPPORT 

81 55/8 15B I/O .. .24 95 

8755 I/O with Eprom , ....6495 

B202 Dyn. RumCont 34.95 

6205/7 <tS 138 Oci-odo-- 3 95 

02 1 2 8 bit l/o 2.75 

8214 Prioritylnt 5.25 

B216 Bus Driver 2.75 

8224 Clock Gen 2.95 

8224-4<4MHi) 975 

8226 Bus Dnver 395 

6T26 Bus Dr.ver 2.95 

8228 Sys. Control ... 5.50 

8233 Sys. Cont. .., ,. 5 50 

8251 Prog. I/O .. 695 

B253 inl. Timer. 

8255 Prog. I/O.... 

8357 Prog. DMA 1695 frJoSO/lSIO] 500 flal 

8359 Prog lm 17 95 FN0508 500 Rf 

8375 CRT CO'.iro.*. 59 95 FN0530 500 & 

8379 Prog. Keyboard . . 1895 f N rj550 500 o fan ge Goran Catnofle 

. ann <•■ ir.ru-.n-r rumc FNDB03 (800) flOO Red Goran CatMode 
OBUU aU^rVHI UniK» FND807(B10] .800 Red 
■ 6810 1 2B x 8 Ram 4 75 H(»OB273J0 600 Red 

6820 PIA... . . 595 HP™2-7300 600 Ital 

6821 PIA.. 6 50 HPeOB2-7?31 300 lied 



TV CHIPS/SOUND 

AY3850C-1 6 Games B/W 4 9 

AY385 15 Color Convener , 2 9 
AY38603-1 Roadrnce Game ..8.9 
AY39605-1 Warfare Game CAL 
AY3B606-1 Wipeoul GamH 9.5' 

AY3B607-1 Shooting Gallery 8.9 
AY38910 Sound Generator . 129 
SN76477 Tl Sound Generalor . 3.9 
MM5320/31 TV Synch Gen 9 9 

MM5369 Prescaler 3.9 

RF Modulalor 3.9 

MM571O0 NSC Color TV .69 

MM57104 Clock Gen 3.7 

RF Modulator w/Audio 8.9 

MSR Modulator 29.9 



WAVEFORM GEN. 

8038 Function Gen 3.95 

MC4024VCO 2.65 

LM566VCO 1.95 

XR2206 Funclion Generalor . 5.25 

SHIFT REGISTERS 

MM500H Dua',25 . . 50 

MM5056N Dual 256 2 95 

MM5060N Dual 128 2 95 

2510ADual 100 •■ 95 

2847 Quad 80 -i 95 

3341 Dual 80 4 95 

3351 40x9FIFO 17.95 

3357 Quad 80 6 95 

9403 16x4 FIFO 24 95 

9408 10 Bit Seg^pnr.-r T95 

CTS DIPSWITCHES 



CTS206-2 
CTS206-4 
CTS206-5 
CTS206-6 



75 CTS206-7 1.75 

.75 CTS206-8 1.95 

75 CTS206-9 195 

.75 CTS206'10 1.95 



Mil 
DL704 
DL707 
„ FND357 
,ti95 FN0501 500 Red 

8-SO FN0503I500) 500 Rarj 



357 Red 



Ccmm. Cathode 
Corm Anode 
Cornn. Cattiooe 
Comm Cattrade 1 -t 
Goran Cattiooe 
Comm. AnoOe 
Comm Anode (+1 
Comm CaUtode 



CONNECTORS (GOLD) 

DB25PIRS232) 3.25 

DB25S Female 3.75 

Hood 1.25 

Set w/Hood, Sale S7.50. 

22/44 WAV, S/T, KIM 2.95 

43/66 WAV. S/T. MOT 6 50 

50/100S-1COConnectorwAv. 4.95 
50/100 S-100 ConnectO'S/t 3.95 



Comm. Anode 



6828 P 

6834-1 512x8 Eprom 

6845/HD46SC5Cfll Conl 

6847 Color CRT 

6850 ACIA, 

6852 Serial Adapie' 



9.95 

16 95 
1195 
43 95 
5 95 
5 95 



nuos 

T1L308 
TIU09 



270 H 



A . 7 Sgl Digil RHD 
Comm. Anode 
Array 5 1 7 

Numerical Display 



6871 A l.OMrHj OSC - 25 95 XAN3063 

6875 825 

6880 Bus Driver 2.95 

MC6848B . .19 95 

6B047 . ..24 95 

1802 SUPPORT CHIPS 



WN30611 

XAN30S1 
XAN3052 
UN30S3 
XAN3054 
XAN30B1 
831 SCD2KRAM 2500 KSSS 



822 SCO 256x4 RAM 
824 CD 32 . 8 HAM 
852 CD 8 b.l 7o 
854 Uan .. 



■6 95 
3 95 
10 95 
TO 95 

856 CD I/O .. ... 8 95 

857 CD I/O .8 95 

1295 

6502 SUPPORT CHIPS 

6520 PIA 7.50 

6622 Mull.. 11 95 

6530-002.0CJ 004 005 21 95 

6532 1995 

6551 1995 

PROMS 

2708 450 ns .8 25 

27086650ns 750 

1702A. . . 495 

2732 74 95 

27165V ..29 95 

2716'5V. 12V. 2995 

2758-5V 2995 

5203AG 13.95 

5204AO ..14.95 

IM 5610 3.90 

SALE 8223 32*8 2.95 

82S11S512xB(TSl 16.95 

82S12332 * B 4 90 

835126 356 <4 4 90 

83S129 356 .4 (1SI 4 90 

82S130512 » 4 (OC> 6.50 

82S23 B.95 

82S131 14.95 

82S137 .... . . .1495 

NOTE: WE PROGRAM PROMS 

CHARACTER GEN. 

,2513-001 (5V) Upper 9 50 

25 13-005 (5V) Lower 10.95 

25 1 3-ADM3 |SV) Lowor 1 4.95 

MCM6571 11 75 

MCM6571A 11.75 

MCM6574 14,50 

MCM6575 1450 



320 Red Amy 

270 Red Alpna Numeric 

.300 Red Comm Anode Right 

300 Red Comm Anode Let! DP 

300 Red Overflow, CA Lell DP 

.300 Rod Comm. Cathode Right 

.300 Grrsfi Comm. Anode Right D 

.300 Green Comm. Ancde Left DP 

.300 Green Overflow CA, Lett DP 

300 Green Comm Cathode. Right 

300 Yellow Comm Anode. Righi 

300 Yellow Comm Anode. Ul* " 

300 Yellow Overflow CA. Left 

300 Yellow Comm CatttoOe F 



DP 



IC SPECIAL PURCHASE 



LF 1 3508 JFET Analog Mulli B bil 
ICM 7045 Precision StopWatch , , , 
ICM 7205 CMOS LED Stopwotcr-.Tm 
ICM 7207 Oscillator Controller. , 
ICM 7208 Seven Decade Counier 

iCM 7209 Clock Generalor 

ICL 7107 y? Digil A/D (LED) .. . 
MC14433P 3', Digit A/D Converter 
ICL 821 1 Vollage Reference 
LM390N Ballery Op. Audio Amp ., 
LM I800N PLL FMSterero . 

LM 1820N AM Radio . 

LM 1850N Ground Fault IC . . . . 

LM 2900N Quad Amplifier 

LM 2901 N (HM) Quad Comparalm 

LM 2917N Freg. to Volt Conv 

AY-3-3550 4'. drgil DMM 

AY-5-3507 40MHz DVM 

MEM 4963 Mosfet Smoke Detector 

27SOB 32 x 8 Prom (IM 56001 

Gl 15M 6 channel Mosfet . '.. . . 

ULN 20O3A 7 channel Driver 

10146 1Kx 1 ECL Ham 

ViCM 1 4505 64 bit Static Ram ... . 

7520/25 50 LM377 . 

148S/1489. 2/199 LM3B7. 

MK50l4Calc..3/1.99 LM 3302 

74S89 3/1.99 LM 4558 . 

7BH05K 6.95 RC4136 . 

LM323K ..4,95 RC4131.. 

MCI 372 . ...8 95 COM 5027 



. 13 95 
.. 1,95 
3/1.00 
3/1 00 
3/ 1 .00 
3/1 00 
2/1. CO 
2/1 00 
2/1.99 
24 95 
9.95 
11.95 



NAKED PC 

Z-BOCPU (Ithaca) 

80B0ACPU 

BK Static RAM (Logos) 

16K Sialic RAM (21 14) . 

32K Sialic RAM (21 14) 

BK Eprom (2708) 

1702 Eprom Board . .. 

270B/2716 Eprom (llhaca) 

Z708/27 16 Eprom (WMC| 

Reailimt.! Clock .. 

ACP Proto Bd. I3M Conn. 1 

Vector 8800 Proto 

Vector 8B03 11 slot MB 
ACP Extender w/Conn .. 
Video lnioiface(SSM) .. 
Parallellntertace (SSMl 
1 3 Slot MolhorBoard (WMC) 32 95 
9Slol MotlierBoard(WMC) 2995 
eSlolMothorle. fundable) . 34.95 
Proc-Tecr, Bare Boards CALL 



•3-: ■■', 
34 95 
24.95 
29 95 
29.95 



. 34 95 
30 00 
34 95 
27 95 

.22 20 
2'.l 9!i 
1R05 
31.95 



COMPUTER SPECIALS 



DISCOUNTS! list sale 

Applell Plusw/!6K 1195. 990 

PET2001-16N 995 895 

Exidy Sorcerer w/ 1 6K 1 099. 

Cromemco Sys III 6990, 6290 

Horizon I w/32K CAL'L 

Pascal Microongme 1995.1595. 

IPSI 1620 DiabloRO 3?96 rrL-95 

Anadei DP 8000 995 B75. 

Centronics Micro S-1 595 525 

Soroc IO 120 995 795 

Telelype Model 43 1349 1 1 50 

HiPlot Piotlor 1085 B99 

HIPIot Digitizer 795 735 



999 750 
549 449 
1150.1099 
149 139. 
995 899. 
375 349 
595 525. 
220. 169. 

295. 249. 

296. 219. 
FREE CASSETTE 



Atari 400 
Tl 99/4 

Leedex 12" Monitc 
Cenlron.es 737 
TrencomT-100 
Trencom T-200 
Sanyo 9" Monilot 
Sanyo 15" Monitor 
Mol22 MHz Moniti 



U ARTS/BAUD RATE 



VERBATIM 
DISKETTES 

100% CERTIFIED ERROR-FREE! 

■ 95 TRACKS. nn-LISlF DENSITY single-sided sv. 
TYPE DESCRIPTION PRICE'BOX If) 

525 Oi Sotl Sectored IRS BO el 



AY5I0I5A/1863I; 
TMS601 1 15V. 121 
IM6402 
1M6JQ3 



id NS ApoC etc 
4.95 525-16 16 Hole Hard MtiopolS 

6 95 a ID I 77 TRUCK DOUBLE DENSITY - SINGLE SIDED 
6 95 SV W/riUS REINFORCEMENT RING 

5.52 5/701 Soli Secloreo THS BO el: 

7.95 $77-10 10 Hole Hard NS A;o*. e!: 

8.95 57/16 16 Hole Ham Mcopots 

??i Qs • « r»"S OOUILt SIDED. DOUBLE DENSITY S'.i 
55001 Sot! Scclwed SA 450 MP! 52 
Hole Hard. BASF. WANGCO 



SOCKET SPECIALS 


14 Pin wyVSI 




i 35 


16 Pin w/w-2L 




40 


18 Pinw/w2L 




55 


20 Pinw/w2L 




75 


40 Pinw/«-;'L 






18 Pin s/i 




15 


23 Pin s/i 




15 


Call (or vcJune 


• 1 





550-11 



16 H 



WD >94 1 9 95 

COM 5016 16.95 

KEYBOARD ENCODERS 

AY5-3376 13.75 

AY5-3600 13.75 

HD0165 9.95 

74C922 9.95 

74C923 9.95 



• 8 \tV* CERTIFIED DISKETTES 

fDfiJti-01 Smi. Single Densily, 3740 S33S0 

F03-30-32 32 Hntd Single Density Snug 33 50 

FDS32-01 Soil UouDle Densily. 3740 4160 

f-0850-01 Soli Do,i!;:o S-JCrl rV,.!.-' L>nh-ly 3740 4080 

VOLUME DEALER PRICING AVAILABLE 
WE ALSO STOCK DYSAN-CALL 



TERMS: Use cnecK. M/C, VISA 
AMEX. CB, or COD COD requires 
25% deposit. Charge Orders please 
include expiration date. Foreign pay 
U.S. Funds. Order by phone, mail or 
TWX. MINIMUM S100O Please in- 
clude magazine issue and phone no. 
SHIPPING: USA add S2.00 for first 
2 lbs For surface add 30e for addi- 
tional lbs For air add 70e lor addi- 
lional lbs. FOREIGN: Add 10% ship- 
ping and handling. COD's S 1.B5 eitra 
Nol responsible lor typos. Some 
items subjeel to pnor sale. We re- 
servo right to limit quantities, some 

Relail pricing may vary from Mail 
Order. We reserve tha right lo sub- 



RETAILSTORESOPEN MON-SAT 
STORE 1310 "B" E. Edlnger STORE 674 El Camino Real 



1 Santa Ana, CA 92705 

Showrooms, Retail, Warehouse 



2 Tustin, CA 92680 

Specializing in Systems 



P.O. Box 17329 Irvine, Calif. 92713 

Direct Order Lines: (714) 558-8813 

(800) 854-8230 or (800) 854-8241 



FOR INTERNATIONAL ORDERS: 
1401 E. Borchard (714)953-0604 
Santa Ana, CA92705 TWX: 91 0-595-1565 



Circle 225 on inquiry card. 



BYTE August 1980 271 



The Supermarket for TRS-80 
Add-on Components 



* 



(and other computers, too) 



■ I II IlfcrVJI^llv? \dl^i?ll Vfcfl V» 



The VISTA V-80 
Disk Drive System 

• 23%more storage capaci 
than TRS-80 ^ 

• 120 day warranty 

• 40 track patch at NO 
CHARGE 





Single drive system $ 395.00 

Two drive system $ 770.00 

Four drive system $ 1450.00 

Two drive cable $ 29.95 

Four drive cable $ 39.95 



The VISTA V-80 Expansion Module 

• Provides douPle density 
modification to your 
current Radio Shack 
interface (lets you format 
diskettes in either single 
or double density). 

• Increases storage 
capacity up to 204K 
Pytes (on single 40 
track drive). 

• Includes all hardware 

$239.00 software 




The VISTA Model II 

• Provides one, two or 
three drives. 

• Adds up to 1.5 million 
bytes of on-line storage. 

• 120 day warranty 

• Does everything Radio 
Shack's expansion 
system will do. ..for less! 

$1000.00 Single drive 

Expansion System 
$1550.00 Two drive Expansion System 
$2100.00 Three drive Expansion System 
$ 525.00 Additional drives alone 





The TRS-80 Printers 

Centronics 730... $945.00 

7x7 dot matrix- 

80 column ^ 

Anadex 

DP8000... $895.00 

9x7 dot matrix- 

80 column _^~^ / 

VISTA 

Printer... $745.00 

5x7 dot matrix- 
80 column 

Cables $27.50 each 

Add On Drives 

MPI B51 40 Track, Double 

Density-204K $275.00 

MPI B52 Dual Head, Double 

Density-408K $375.00 

Siemens FDD100-5 40 Track Double 

Density 204K $275.00 

Siemens FDD100-5 Flippy, 

records both sides $290.00 

Siemens FDD100-8 8" Single 

Sided Drive $448.00 



Other Products 

1. VISTA Verbatim diskettes (hard or soft sector) Certified 
40 track $ 38.95 

2. 16K RPM upgrade kits, guaranteed for 120 days. 
PRIME PRODUCT $ 74.50 

3. NEW! DOS + $ 110.00 

4. LNW expansion bare board $ 66.95 

5. H.C. Pennington book, TRS-80 Disk 

and Other Mysteries $ 18.95 

6. DDT Disco-Tech disk drive timer $ 19.95 

7. Cryptext (An Encryption Module) $299.00 



The VISTA V-200 for Exidy 

• Completely packaged system, tested and ready to plug in, includes: 
power supply, two 40 track drives, case, controller, all cabling and 
total CPM documentation. 

• Storage capacity from 400K to 1.2 meg. ^ 

• System software-VISTA CP/M Disk Operating System and BASIC-E Compiler' 
recorded on 5-1/4" diskettes. 

Price: Starting as low as $1199.00 



iflSfl 



CALL TOLL-FREE 800-854-8017 



•TRS-80 is a registered trademark of Radio Shack. 

The Vista Computer Company 1401 Borchard Street* Santa Ana, California 92705 • 714/953-0523 




272 BYTE August 1980 



Circle 224 on inquiry card. 



PRIORITY ONE ELECTRONICS 



THE STAR 
MODEM 

from Livermore 



STARS & STRIPES 
SPECIAL 

LIST PRICE 

199.00 

OUR CORNER 
THE MARKET PRICE 

$139.00 




FEATURE 

FITS GTE HANDSETS! 



The STAR modem from Livermore repre- 
sents a significant breakthrough in the 
development of acoustic modems. The 
small, lightweight case houses a high- 
performance modem that competes with 
the highest quality standard-sized couplers 
available. Yet, because of its cost effective 
design, the STAR has become the 
price/performance leader in the industry. 
CIRCUITRY 

The switchable, four-section bandpass 
filter provides the user with excellent out- 
of-band rejection to assure accurate pro- 
cessing of the received carrier, even at 
signal levels of less than -47 dBm. Fur- 
ther, the proven soft limiter and phase lock 
loop discriminator yields data that is 
essentially jitter free. 



The oscillator is built using highly stable, 
state-variable circuitry that delivers a near- 
ly harmonic free, phase coherent sine wave 
to the telephone network, assuring com- 
patibility with all other 103 type modems. 
Because of the pureness of the sine wave, 
the STAR modem exceeds even the str- 
ingent harmonic requirements of all CCITT 
countries. 
CARRIER DETECT 

To assure accurate teleprocessing connec- 
tions, the carrier detect circuitry prevents 
the modem from attempting to operate 
when excessive noise would produce er- 
rors or cause marginal operation. The cir- 
cuitry also has a special amplitude sensor 
that prevents chatter when the received 
signal fades. 



EXCLUSIVE ACOUSTIC CHAMBERS 

The exclusive triple seal of Livermore's new 
flat mounted cups locks the handset into 
the acoustic chamber yielding superior 
acoustic isolation and mechanical 
cushioning. Designed to adapt to most 
common handsets used throughout the 
world, the STAR offers the utmost in flex- 
ibility and transmission reliability. 
SELF TEST 

The self test feature on the STAR allows 
the user to verify total operation of the 
acoustic modem by using the terminal in 
the full duplex mode. No need for remote 
assistance in diagnosing terminal or 
modem problems. 

Utilizing the experience gained from 
building high quality couplers for over 
twelve years, Livermore has designed a 
coupler superior to any in its class for cost 
efficiency in industrial, commercial, 
business or home situations. You can see 
why we call it the STAR! 
SPECIFICATIONS 
Data Rate. to 300 baud. 

Compatibility. Bell 103 and 113; CCITT. 
Transmit Frequencies.* Originate - 1070 
Hz/Space, 1270 Hz/Mark; Answer - 2025 
Hz/Space, 2225 Hz/Mark 
Receive Frequencies.* Originate - 
Hz/Space, 2225 Hz/Mark; Answer 
Hz/Space, 1270 Hz/Mark. 
Frequency Stability. ±0.3 percent. 
Receiver Sensitivity. -50 dBm ON 
dBm OFF. 
Transmit Level. - 15 dBm. 
Modulation. Frequency shift keyed (FSK). 
Carrier Detect Delay. 1.2 seconds ON; 120 
msec OFF. 

EIA Terminal Interface. Compatible with RS 
232 specifications. 

Teletype Interface. 20 milliampere current 
loop. 
Optional Interfaces. IEEE 488; TTL; TTY 43. 

'International (CCITT) frequencies 
available. 

Switches. Originate/Off/Answer; Full 
Duplex/Test/Half Duplex. 
Indicators. Transmit Data, Receive Data, 
Carrier Ready, Test. 

Environmental. Ambient operating 
temperature 5° C. to 50° C. Relative humidi- 
ty 10 to 90 percent (non-condensing). 
Power. Suppled by 24 VAC/150 MA UL/CSA 
listed wall-mount transformer. Input 115 
VAC, 2.5 watts. (A 220 VAC, 50 Hz adaptor 
is available upon request.) 
Dimensions. 10"x 4"x 2" 
Weight. 1.75 lbs. (2.2 lbs. shipping weight 
including AC adaptor.) 
Warranty. Two years on parts and labor, ex- 
cluding the AC adaptor which carries th 
manufacturer's warranty. 



2025 
1070 



-53 



CENTRONICS 

730 Dot Matrix Printer 

LIST PRICE $795.00^^ 

SALE PRICE 

$695.00 




STANDARD FEATURES: • 50 Characters/second • Characters/line • 10 characters/inch 
• 3-way paper handling system • 7 x 7 dot matrix • 96 character ASCII • microprocessor I 
* electronics • unidirection print at 50 ips ■ high speed return approximately 10 ips • 21 f 
Ipm with 80 columns printed * 5B Ipm with 20 columns printed • 80 character butter • 6 J 
Ipi vertical • Centronics Colors and logo 

FORMS HANDLING: Roll Paper; 8 5 In. x 5.0 dia. with 1 in. core maximum dimension. 3 5 | 
m. wide with .38 in. core minimum dimension. Fan Gold: 9.0 in. 122.9 cm. wide pin to pin ] 
9.5 in, /24.1cm wide overall. Up to 3 ply paper with 2 carbons (total thickness not to ex- 
ceed .012 inches) Cut Sheet: Maximum width 8.5 inches. 

RIBBON SYSTEM: Continuous ribbon 9/16" (14mm) wide. 20 yards (18.3 meters) long. 
Mobius Loop allows printing on upper and lower portion on alternate passes 

OPERATOR CONTROLS: Power on/otl Reset Switch -allows disabling of printer without | 

dropping AC. 

DATA INPUT: 7 or 8 bit ASCII parallel. TTL levels with strobe. Acknowledge pulse i 

dicates that data was received 

PHYSICAL DIMENSIONS: Weight: less than 10 lbs./5 kg Width: 14.5 inches/37 cm 

-Depth: 1 1.0 inches/28cm -Height: 4.89 inches/ 13cm -Dimensions exclusive of roil paper 

$19.95 SHIPPING WEIGHT: 14 lbs. 




•TRS80 -CENTRONICS 70 TRS-80 Inteface Cable 

PRIORITY ONE ELECTRONICS 

16723K Roscoe Blvd. Sepulveda, CA 91343 

Terms: Visa, MC, BAC, Check, Money Order. U.S. Funds Only. CA residents add 6% sales tax, 
Minimum order $10.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. 
MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to 
change without notice. We will do our best to maintain prices thru Auq 1980. 
'SOCKET and CONNECTOR prices based on GOLD, not exceeding $500 per oz. 

'Sale Prices are for prepaid orders only credit card orders will be charged appropriate freight 



FOR MORE INFORMATION SEE I 
OUR 52 PAGE AD in JANUARY] 
BYTE OR SEND $1.00 FOR| 
CATALOG 
• Sale Prices are for prepaid I 
orders only • Quantities are | 
limited, subject to prior sale 
CREDIT CARD ORDERS WILL Bl 
CHARGED APPROPRIATE 
FREIGHT 



Circle 228 on inquiry card. 



PRIORITY ONE ELECTRONICS 



PRIORITY ONE ELECTRONICS 



TRS-80/APPLE 

MEMORY EXPANSION KITS 
4116's RAMS 



8 for $48°° -<. 

ADD $3.00 FOR PROGRAMMING JUMPERS 
FOR TRS-80 KEYBOARD 

4116's 100 pes & UP $5.20 each 
1000 DCS & UP $4.45 each 



Reg. Price Sale Price 

SDS-EXPANDORAM I KIT OK $220.00 $210.00 

SDS-EXPANDORAM I KIT 16K $249.00 

SDS-EXPANDORAM I KIT 32K $299.00 

SDS-EXPANDORAM I KIT 48K $349.00 

SDS-EXPANDORAM I KIT 64K $398.00 

. . $230.00 $220.00 

$250.00 

$325.00 

$390.00 

$459.00 



Factory Rebate Sale 

When you purchase any SD SYSTEMS 
Computer Board, either kit or A&T from 
PRIORITY 1 ELECTRONICS, you will 
receive a COUPON FOR A $25.00 CASH 
REBATE direct from the Manufacturer, SD 

SYSTEMS. Combine the Rebate with our already low prices, and you can 

hardly afford to pass up this special offer. 

For more information, see last month's issue of Byte, or our catalog. 




SDS-EXPANDORAM II KIT OK 
SDS-EXPANDORAM II KIT 16K 
SDS-EXPANDORAM II KIT32K 
SDS-EXPANDORAM II KIT 48K 
SDS-EXPANDORAM II KIT64K 



Reg. Price Sate Price 

SDS-VERSAFLOPPY I KIT $250.00 $220.00 | 

SDS-VERSAFLOPPY II KIT $350.00 $299.00 | 

SDS-VDB8024 KIT $370.00 $320.00 

SDS-PROM-100 KIT $200.00 $175.00 

SDS-SBC-100 2 Mhz KIT $295.00 $265.00 

SDS-SBC-200 4 Mhz KIT $320.00 $289.00 

SDS-Z80 STARTER KIT $340.00 $299.00 



SD Systems Kits carry a 90 day limited warranty from SD Systems. 4116 ICs 
supplied by Priority 1 Electronics for use in SD Expandorams carry a 1 year 
limited warranty from Priority 1 Electronics. 



Compare our Sale Prices, and then don't forget your Rebate! 



<T 



COMPUTER 
SYSTEMS 
INC. 



Z+80CPU 



IEEES-100 
COMPATIBLE 



+ IK Ram On Board + 2 Programmable Timers 

+ Switch Selectable 2 or 4 MHZ 

♦ Power On Jump to On-Board IK or 
2K EPR0M (2708-27 162732) Can be 
Addressed on any IK, 2K or 4K Boundary 

Bare Board $ 45.00 A&T 



EXPANDABLE + DYNAMIC MEM0RY(16K to 64K) 



Kit 



$169.95 



IK Memory Kit $ 12.00 



Programmable Baud Rate Selection (1 10 to 9600) 
On-Board EPR0M May be Used in Shadow Mode, 
Allowing Full 64K RAM lo be Used 
On-Board USART for Synchronous or Asynchronous 
RS-232 Operation (On-Board Baud Rate Generator) \ 
$229.95 



+ Works With Cromenco Systems + 
♦ Uses 3242 Refresh Chip ♦ 

+ 4 Layers Mean A Quiet Board + 

I Bare Board { 49.95 32K Kit 

16K Kit $295.95 32KA&T 

UfiKA&T $345.95 48K Kit 



Bank Selectable Write Protect 
Phantom Output Disable 
Switch Selectable Output Disable 

$369.95 48KA&T $494.95 

$419.95 64KKit $519.95 

$444.95 64KA&T $569.95 



CLOCK CALENDAR + 

+ Time of Day in Hours, Minutes and Seconds 
♦ 24 Hour Time Format + 

+ Month and Day Date Function + 

Bare Board $45.00 Kit $99.95 A&T $149.95 



Simple Read Instructions Allow Simple 

Interface to Basic, CPM, Etc. 

Will Run With 4 MHZ Processors 

Can be Located at any Group of 4 I/O Port Addressecl 



3 LOBO 8" DISK DRIVE CABINET 




New from Lobo. a dual Cabinet with power supply. 
and internal data cable hook-up 

• Cabinet accepts 2 801R. 800R, FD120. or FD200 
style disk drives. 

• Power Supply for 2 drives. 

• Assembled, tested and guaranteed by Lobo Drives. 

• Shipping Weight 30 lbs. 

LFJO — DUAL 8 PCS $329.00 

BUY CABINETAND DRIVES AND SAVE 



WITH 1 DRIVE 
LBO-801R-1PSC . . 



WITH 2 DRIVES 
LBO-801R-2PSC .... >1250™ 



'775" 

DISC DRIVE ONLY 
SHU-801R $499.00 

EXTERNAL DATA CABLES 
CARDEDGE TO CARDEDGE CARDEDGE TO SOCKET 

PRI-50CE-CE '19.95 PRI-50CE-SKT '19.95 



MEMORY HEADQUARTERS 

2716 16K 5 Volt only EPROM. .«22*» ea. 

10/«200° 

2708 8K 450ns EPROM 8/'55 00 

s 8 5 ° ea. 

2114-3L 1Kx4 300ns Low Power. 8 s 45 00 

100 + s 4 60 ea. 

5257-3L4Kx1 300ns Low Power. .8/ $ 55°° 

100 + s 5»ea. 

2102AL-2 UP 250ns in lots of 20 . 1.25 ea, 

100+ 1.10 ea. 



SPECIAL PURCHASES 



POWER SUPPLY 
5 Volt 3 Amp w/OVP 

Input 110/220V Open Frame 
1 9 95 

MAGNIFIER 

with T9 fluorescent tube 
List $94.95 
Sale s 49 95 

LDU-MG-10A S49.95 



Hitachi V302 





30MHZ DUAL TRACE 
OSCILLOSCOPE 

LIST 945.00- SALE S 798°° 

TV sync-separater circuit • Complete with 2 probes 

High-sensitivity 1mV/div „• CHI. CH2. DUAL. 

Sweep-time magnifier ' ' ADD. DIFF. 

CO times) Vertical Detlection Modes 

Z-axis input (intensity • V152 Oual Trace 

modulation) 15MHZ - no delay sweep 



Signal delay line 
X-Y operation 
Trace 
Rotation 



LIST 695.00 



SALE s 595 



00 




PRIORITY ONE ELECTRONICS 

16723K Roscoe Blvd. Sepulveda, CA 91343 

Terms: Visa, MC, BAC, Check, Money Order, U.S. Funds Only. CA residents add 
Minimum order $10.00 Prepaid U.S. orders less than $75.00 include 5% shipping 
MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Pri 
changewithout^ notice. We will do our best to maintain prices thru Aug 1980 



6% sales tax, 
and handling, 
ces subject to 



■SOCKET and CONNECTOR prices based on GOLD, not exceeding $500per oz. 

'Sale Prices are for prepaid orders only credit card orders will be charged appropriate freight 



PRIORITY ONE ELECTRONICS 



FOR MORE INFORMATION SEEl 
OUR 52 PAGE AD in JANUAflyl 
BYTE OR SEND $1.00 FORI 
CATALOG 
• Sale Prices are for prepaid I 
orders only • Quantities ar 
limited, subject to prior sale 
CREDIT CARD ORDERS WILL BE I 
CHARGED APPROPRIATEj 
FREIGHT 



Circle 229 on inquiry card. 



Com pu Pro 



PRIORITY ONE ELECTRONICS 



- MSR 



MEET THE ECONORAM FAMILY 

all ECONORAMS from COMPUKIT include: 



• Fully static memory used throughout to promote reliable operation and 
facilitate direct memory access. (DMA) 

• 4 MHz with Z80 - 5 MHz with 8085 

• Buttered tri-state outputs and buffered inputs. 

• All lines buffered: address and data lines buffered to 1 low power Schottky 
TTL load, all other lines buffered to less than 1 TTL load. 

• Onboard regulation. 

• DIP switch address selection and deselection (no wire jumpers). 

• Low power Schottky support ICs. 

• S-100 boards have WRITE strobe selections switch ■ allows use of memory 
with or without front panel. 

Most ECONORAMs come In 3 forms; UNKIT (UKT) • (this means that all sockets, disc capacitors 
qualified under the Certified System Component (CSC) high-reliability program (200 hour burn-in, g 
leplacemeni in event ot failure with 1 year of invoice date). 



All ICs are socketed (including support chips) 

Unique multi-block configurations for addressing flexibility. 

Industry standard board sizes. 

High quality, double sided, plate through, solder-masked and legended 

circuit board. 

LOW current consumption and guaranteed specs. 

1 year limited warranty (not just 90 days). 



■jfif- 



,^ e 



are already soldered in place for easy assembly), fully assembled & tested (A&Ti. oi 
uaranteed 4MHz operation over full temperature range, serial numbered, immediate 




ne* 



8K 

ECONORAM 

MA 



We realize that this may not look like the 8K, Econoram II board you've known and loved 
for so many years; however, at Godbout.good things don't come to an end -they just get 
better! Our NEW 8K Econoram MA board retains all the best selling features of the old 
Econoram II PLUS is now 4 MHz STANDARD -still static -with ultra low power consump- 
tion. S-100 compatible. Single supply required - guaranteed maximum current under 
900mA. Typical boards draw 700 to 800mA. Phantom feature is included on the new 
Econoram MA and is switch selectable. Organized as two 4K independently addressable 
blocks. Includes switched WRITE protect - block and board disable. Also, has provision 
for memory management. Shipping Weight 2 lbs. 

Reg. Sale 

GBT - ECONORAM MA UKT $169.00 $159.00 

GBT - ECONORAM MA A&T $189.00 $169.00 




CK022 S-100 
INTERFACER 



Our new I/O board gives you unparalleled flexibility and opeiating convenience. We include such 
features as: 

• 2 independently addressable serial ports (dip switch selectable addresses) 

• Real LSI hardware UARTs for minimum CPU housekeeping 

• RS232C. current loop (20mA), & TTL signals on both ports 

• Precision, crystal-controlled Baud rates up to 19.2K Baud (individually dip switch selectable) 

• Transmit 8 receive interrupts on both channels, jumperable to any vectored interrupt line 

• Industry standaid RS232 level converters with five RS232 handshaking lines per port 

• Optically isolated current loop with provisions for both on-board & off-board current sources 

• UART parameters, interrupt enables & RS232 handshaking lines are software programmable with 
power-on hardware default to customer specified hard-wired settings for maximum flexibility 

• Pod connectors mate directly to ribbon cable & DB25 connectors in standard pinouts 

• RS232 lines will conform to either master or slave configurations 

• Board gives full leature operation with both 2 & 4 MHz systems 

• Low power consumption. +8V @ 450mA; +16V @ 150mA; -16V (3> 70mA max. 

• No sottwarc initialization required for board operation, although board parameters may be altered Dy 
software 2 lbs. 

Reg. Sale 

GBT- INTERFACER I UKT $199.00 $189.00 

GBT- INTERFACER I A&T $249.00 $219.00 



NEW! 32K X 8 ECONORAM X 

Static storage for the S-100 buss. 

Static storage for the S-100 buss. Guaranteed 4 MHz operation. Config- 
ured as two 8K and one 16K block, all independently addressable, protect- 
able & enableable. Suitable for use in phantom systems. Extra select/de- 
select qualifiers for systems using more than 64K of memory make this board 
the ideal building block for large memory systems. Maybe you can't believe 
the low pricing - but you can count on the Econoram performance! Also 
available populated to 16K. Shipping Weight 2 lbs. 

Reg. Sale 

GBT- ECONORAM X 16KUKT $329.00 $308.00 

GBT- ECONORAM X 16K A&T $379.00 $319.00 

GBT - ECONORAM X 32K UKT $599.00 $559.00 

GBT - ECONORAM X 32K A&T $689.00 $589.00 



INTERFACER II 



The new Interfacer II I/O board incorporates one channel of serial I/O with 
all the features of the INTERFACER dual RS232 serial board, plus 3 full 
duplex Parallel ports. The serial section includes all the features you've come 
lo expect - a hardware UART, on-board crystal controlled Buad rate genera- 
tor, hardware/software programmability, RS232 handshaking lines with real 
RS232 drivers, current loop & TTL drivers, full interrupts and more!!! The 
parallel selection utilizes LSTTL octal latches for latched input & output data 
with 24mA drive current, attention, enable & strobe bits for each parallel port 
(each with selectable polarity), interrupts for each input port, separate 25 pin 
connectors with power for each channel and a status port for interrupt mask 
and port status. All in all - an incredibly flexible and easy to use board. 

Reg. Sale 

GBT - INTERFACER II UKT $199.00 $189.00 

GBT - INTERFACER II A&T $249.00 $219.00 



ECONORAM 
XIIIA-32 




32K BANK SELECT! S-100 compatible. 4MHz guaranteed operation (0-70 C.) Features 
two 16K blocks independently addressable on 16K boundaries. Two independent banks 
-individual phantom - 256 ports DIP switch selectable . .each block may be deselected 
with a single switch. Perfect for use in Alpha Micro Systems. Marinchip & others. Uses 4K 
x 1 low power STATIC rams. Current consumption guaranteed 3500mA max. Shipping 
Weight 2 lbs. 

Reg. Sale 

GBT - ECONORAM XIIIA 16K UKT S349.00 S329.00 

GBT - ECONORAM XIIIA 16K A&T $419.00 S369.00 

GBT - ECONORAM XIIIA 24K UKT S479.00 $449.00 

GBT - ECONORAM XIIIA 24K A&T $539.00 $479.00 

GBT - ECONORAM XIIIA 32K UKT $649.00 $598.00 

GBT - ECONORAM XIIIA 32K A&T $729.00 $649.00 




ECONOROM 
2708 



Has provisions for wait states for 4MHz operations. Configured 
as four 4K blocks - each independently addressable and disab/e- 
able. Power-on jump. Does NOT include 2708s. Includes all sup- 
port chips, sockets, regulators, heat sinks, etc. Sold in UNKIT form 
only. Shipping Weight 2 lbs. 
GBT - ECONOROM 2708 UKT $85.00 



c# 



$ 



t vN 



Reg. 



GBT-SPECTRUM (Color graphics) KIT. 339.00 
GBT-SPECTRUM (Color graphics) A&T. 399.00 
GBT-CPU-Z80 KIT 225.00 



Sale GBT-CPU-Z80 A&T 

319.00 GBT-CPU-8085 KIT 

349.00 GBT-CPU-8085 A&T 

210.00 GBT-CPU-8085/8088 KIT. 



Re9- Sale ^ ^ 

.295.00 269.00 $V ^ Reg. Sale 

.235.00 220.00 GBT-CPU-8085/8088 A&T 495.00 449.00 

.325.00 259.00 GBT-BOX-DESK (S-100 Mainframe). ... 289.00 269.00 

.385.00 365.00 GBT-BOX-RACK (S-100 Mainframe). . .329.00 309.00 



ECONORAM XIV 



16Kx8forS-100. Addressable on any 4K boundary. Direct addressing on up to 24 address lines. Fully meets IEEE S-100 buss, specs. Low power, hi speed 
static memory. Operates up to 5MHz with newest 8085/8086/8088 CPUs. Can be used with 8080, Z80. 8085, 8086, 8088, Z8000, etc. 

Reg. Sale Reg. Sale 

GBT- ECONORAM XIV UKT $299.00 $279.00 GBT - ECONORAM XIV A&T $349.00 $298.00 



Circle 229 on inquiry card. 



PRIORITY ONE ELECTRONICS 



S-100 VOICE 

The ARTICULATOR board allows 
you to record, store, and 
playback any vocabulary on your 
S-100 computer. Input speech is 
digitized by the ARTICULATOR 
and sent to the computer via an 
on-board port for storage at 1K 
to 2K bytes/sec. This data is then 
sent back from the computer to 
the ARTICULATOR for very high 
quality playback. On-board VOX 
switching minimizes memory 
storage requirements. 

PRICE — $319 A&T 
AVAILABLE NOW 

Quintrex, Inc., 9185 Bond 
Shawnee Mission, Ks. 66215 
(913) 888-3353 




SURPLUS ELECTRONICS 




ASCII 



ASCII 



IBM SELECTRIC 

BASED I/O TERMINAL 

WITH ASCII CONVERSION 

INSTALLED $645.00 

• Tape Drives • Cable 

• Cassette Drives • Wire 

• Power Supplies 1 2V 1 5A, 1 2V25A, 
5V35A Others, • Displays 

• Cabinets • XFMRS < Heat 
Sinks • Printers • Components 
Many other items 
REFUNDABLE FIRST ORDER 
WORLDWIDE ELECT, INC. 

130 Northeastern Blvd. 
Nashua. NH 03062 

Phone orders accepted using 

VISA or MC 

Call Toll Free 1-800-258-1036 



Circle 230 on inquiry card. 



Circle 231 on inquiry card. 



OHIO 

SCIENTIFIC 

SYSTEMS 

CALL FREE FOR OUR. PRICES 

(800) 558-0870 

or 

WRITE FOR CATALOG 

FARAGHER& 
ASSOCIATES 

7635 BLUEMOUND 

MILWAUKEE, WI 53213 

(414) 258-2588 

In Wisconsin 



PASCAL 

For programmers learning or desir- 
ing to learn PASCAL for the APPLE 
computer. 

LEARN BY 
EXAMPLE 



Thre e pra c tic a 1-us e ful PAS CAL pro- 
grams (Text & Code) are now 
available on minidisk for only 
$55.00. Filecreate, fileupdate, and 
filesearch will help you produce in 
just a very short time. Order today 
from: 

Personal Programs By Victor 

P.O. Box 60034 
Sunnyvale, CA 94086 

ICA. Residents add S3.57 Tax) 

CUSTOM PROGRAMS UPON 
REQUEST 



Acoustic Coupler Sale 




Sl45ea.* 

•Texas Residents Add 5% Sales Tax 



• 1 Yr Warranty 

(RTN to Factory) 

• Latest Technology 

(Phase Lock Loop) 

• Up to 300 Baud 

•EIA and/or 20 MIL 

Technology Design 300 



Please Rush: Qty_ 
To: 



. TD300 Coupler 



D Check Enclosed zip code 

Master Charge No 

Visa No. 

Exp. Date 

Signature 

Mail to: 

TBI 1 1332 Mathis Ave. /Suite 109 



Dallas. Texas 75229/21 4-247-1 053 



Circle 232 on inquiry card. 



Circle 233 on inquiry card. 



Circle 234 on inquiry card. 



61 Dysan 

^CORPORATION 



Solve your disc problem*, buy 100% surface 
toted Dyun diskettes. All orders •hipped 
from stock, wtthfn 24 hour*. Call toll FREE 
(800) 235-4137 for price* and Information 
Vfea and Master Card accepted. AD orders 
sent postage paid. 




PACIFIC 
EXCHANGES 

100 Foothill Blvd. 
San Luis Obispo. CA 
93401. (InCal. call 
(805) 543-1037.) 



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With This Ad 

HAZELTINE 1420 $780 

CENTRONICS 779 WjTRACTOR $969 
NEC SPINWRITER $2250 

Get the Catalog 

& 
Our Low Prices 



©, 



DATA PRODUCTS 
MAINTENANCE CORP. 



9460 Telstar Avenue 
El Monte, CA 91731 



(213) 573-5991 
1714) 994-4180 



Circle 235 on inquiry card. 



Circle 236 on inquiry card. 



Circle 237 on inquiry card. 



©IEMP& IS READY . if L 



Z-80 CPU 




DOUBLE/SINGLE 
DISK CONTROLLER 




Two serial ports, three par- 
allel ports. 2/4 MHz, on 
board Prom Monitor Phan- 
toms. {Less cable and Mon- 
itor). A & T $325.00 



Two stage phase lock loop 
circuitry for greatest relia- 
bility, data transfer at maxi- 
mum rate. Transparent den- 
sity selection. 8" or 5" op- 
eration 2 or 4 MHZ (Some 
restrictions on DMA). 
DMA — $425.00 
STD. — $385.00 



16K, 32K 
STATIC RAM 




Worlds most reliable mem- 
ory, responds to extended 
address lines A16, A17, 
cool running, fast. 
16K-$395.00 32K-S650.00 



32K, 48K, 64K 
DYNAMIC RAM 



Bill ■!■• 
Ill ■ ■ I II 

■III III 



Basic dynamic board tested 
to run at 4MHZ with our 
Z-80 board. 4116 chips at 
200 nanosecond speed in- 
sures most reliable datasto- 
rage. Double density and 
DMA compatible. 
32K-$580.00 48K-$640.00 
64K-$750.00 



32K, 48K, 64K 
ERROR DETECTING 
Cromenco/ Alfa Micro 




State of the art develop- 
ment. Parity generation and 
error detection. Compatible 
with 16 bit CPU designs. 
16K bank, select under soft- 
ware control. 4MHZ Z-80, 
8086, Cromenco, Alpha Mi- 
cro compatible. 
32K-$650.00 48K$725.00 
64K-$850.00 



FLOPPYS 



TELEVIDEO 912 





TELEV1DEO 920 




8" Shugart $550.00 

8" Siemans $525.00 

5" Siemans $350.00 

(Double Sided) 

8" CDC $675.00 

8" Remex $645.00 

FLOPPY DISKS 

D YS A N Quality 



80 x 24— Lower case des- 
cenders. Teletype or type- 
writer keyboard 110/220 
VAC. 50 to 19. 2K Baud 
Hex entry pad. Similar to 
SOROC but better looking 
with NO FAN NOISE 



Similar to TV 912 but has 
programmable functions 
keys across top. Excellent 
for WORDSTAR Text Edi- 
ting. 



WINCHESTER/SHUGART 
SA 1000 






WINCHESTER/CENTURY 
DATA SYSTEM 
(Hunter Shown) 




5 megs now expandable to 
10, works alongside floppy 
disk drive for expanded 
storage. Use with controller 
below. 

$1950.00 



20 megs expandable to 
40 — Marksman series, plugs 
into our CPU parallel port 
or MP/M board drive, cabi- 
net, power supply, 2.0 Bios. 
$4850.00 



MPM®l/0 TIMER 



ViM 



COMING 
SOON 




WINCHESTER/FLOPPY 
INTERFACE 



SOFTWARE/ 
CABLES/PROMS 



8" SSSD $4.25 

8"SSDD $5.50 

8" DSDD $7.60 

5"SSDD $4.10 

(Boxes of 10 only) 



Designed for MP/M® soft- 
ware of Digital Research. 6 
users serial port, three 8 bit 
parallel ports for hard disk. 
Timer and vectored in- 
terrupt. 

®TM Digital Research 



Keyboard input, Z— 80 Pro- 
cessor, on board RAM 
makes this a non-memory 
mapped substitute for a 
terminal when mated with 
a keyboard. 

$430.00 



COMING 
SOON 



Allows mixing of Shugart 
Winchester and floppy 
drives on same cable when 
used with DP-DSK. Sup- 
plied with software Bios 
for MP/M®and 2.0 
<8>TM Digital Research 



® 
CP/M 2.2. 



MP/MV . . . . 
2708 Monitor 
2716 Monitor 
Disk 50 Pin 
RS-232 . . . 
CPU to Back 
Disk DC . . 
Disk AC . . 
Winchester . 



$150.00 
$350.00 
$ 25.00 
$ 40.00 
$ 22.00 
15.00 
32.00 
4.50 
2.50 
28.00 



[(JMBJIilflilU 



new mm mm mmm 



S-100 MAINFRAME 




• Twin Verticle Drive 
Mounting, Fits Shugart, 
Siemans, Etc. 

• Key-Lock Switch 

• Detachable 
Power/Mother Module 



INCLUDES 

• Detachable Drive LI, - 

D |,u.,_ mUUULt 

Platform SHnWN AT 

• 12-Slot Motherboard, Spur 

Fully Terminated mum - 

LESS DRIVES $849.00 

INTRODUCTORY SPECIAL 



S-100 MODULE 



• 30Aof+8V 
6A of ±16V 

• Disc Power Supply 

6A of +24V 
5A of +5V 
1A of -5V 

• 220V or 110V AC 

50 or 60 Cycle Operation 

• Connectors Supplied 
For Up To 4 Drives 

• OPTIONAL Fans Mount 
Neatly On 1 Side For 
Forced Air Cooling 




$249.00 

INTRODUCTORY SPECIAL 



West' 

DELTA PRODUCTS 

15392 Assembly Lane, Unit A 

Huntington Beach, CA 92649 

TELEPHONE: (714) 898-1492 

Circle 239 on inquiry card. 




East: 

DELTA PRODUCTS 

11 Edison Drive 
New Lennox, IL 60451 
TELEPHONE: (815) 485-9072 



TELEX: 681-367 DELTMAR HTBH 



Circle 240 on inquiry card. 



6502 7.45 10 @ 6.95 50 @ 6.55 1 
6502A 840 10 @ 7.95 50 7.35 1 
6520 PIA 5.15 10® 4.90 50 @ 4.45 
6522VIA 7.15 10® 6.95 50® 6.45 
6532 7.90 10 @ 7.40 50 @ 7.00 1 



2114-L450 
2114-L300 
2716 EPROM 
4116-200 ns RAM 
6550 RAM (PET 8K) 
21L02 

S-100 Wire Wrap 
S-100 Solder Tail 



4.75 20 <S> 4.45 1 

5.95 20 @> 5.45 1 

21.00 5 i 19.00 
7.00 



2.85 
2.35 



00 @ 
00 @ 
100® 
100® 
00 ® 
00 ® 
00 ® 



6.15 
6.90 
4.15 
6.00 
6.60 
4.15 
5.10 



10 ® 17.00 

8 ® 6.25 

12.70 

.90 

10 ® 2.65 

10 ® 2.15 



CASSETTES— AGFA PE-61 1 PREMIUM 

High output, low noise, 5 screw housing, labels. 

C-10 10/5.65 50/25.00 100/48.00 

C-20 10/6.45 50/29.50 100/57.00 

C-30 10/7.30 50/34.00 100/66.00 

All other lengths available. Write for price list. 



DISKS 

(write tor quantity prices) 

SCOTCH 8" Disks 
SCOTCH 5.25" Disks 
Verbatim 5.25" Disks 
Diskette Storage Pages 
Disk Library Cases 
BASF 5.25" Disks 
BASF 8" Disks 




8" - 2.95 



10/S31.00 
10/ 31.50 
10/ 24.50 
10/ 3.95 
5" -2.15 
10/ 28.00 
10/ 29.00 



ATARI— INTRODUCTORY SPECIAL 

Atari 400, Atari 800, all Atari Modules 20% OFF 



Commodore CBM- 
PET SPECIALS 

-Up to $235 free 
/</ merchandise 
Ay with purchase of one of 
<C following CBM-PET 
items: 

8032 32K-80 column CRT 
8016 16K-80 column CRT 
8050 Dual Disk Drive-950.000 bytes 
CBM Modem-IEEE Interlace 
CBM Voice Synthesizer 
8N full size graphics keyboard 
1 6N full size graphics keyboard 
32N full size graphics keyboard 
1 6B full size business keyboard 
32B full size business keyboard 
2040 Dual Disk Drive-343,000 bytes 

2022 Tractor Feed Printer 

2023 Pressure Feed Printer 
C2N External Cassette Deck 
Used 8K PETs (limited quantities) 




**** EDUCATIONAL DISCOUNTS **** 

Buy 2 computers, get 1 FREE 



CBM Full Size Graphics Keyboard 
CBM WordPro l-for 8K PET 
CBM WordPro 11-16 or 32K, 2040, Printer 
CBM WordPro III-32K. 2040, Printer 



74 
25 



178 



VISICALC for PET (CBM/Persunal Software) $128 

CBM Assembler/Editor (disk) 89 

CBM General Ledger, A/P, A/R NEW! 270 



115 E. Slump Road 
Montgomeryville, PA 1 8936 



Programmers Toolkit-PET ROM Utilities $ 44.90 

PET Spacemaker Switch 22.90 

Dust Cover for PET 7.90 

IEEE-Parallel Printer Interface for PET 79.00 

IEEE-RS232 Printer Interface for PET 149.00 



215699-5826 A B Computers 



Centronics 737 Proportional Spacing Printer $845 

NEC Spinwriter-parallel 2450 



SYM-1 $209 with 4K RAM S 238 

SYM BAS-1 BASIC in ROM 85 

SYM RAE-1/2 Assembler in ROM 85 

MDT 1000 Synertek Development System 1345 

KTM-2/80 Synertek Video Board 349 

KIM-1 (add $34 for power supply) 159 

Seawell Motherboard-4K RAM 195 

Seawell 16K Static RAM-KIM, SYM, AIM 320 

S-100 Static RAM kit SALE 198 

Leedex Video 1 00 1 2" Monitor 1 29 

Zenith Z1 9 Terminal (factory asm.) 770 

KL-4M Four Voice Music Board for PET S34.90 

Visible Music Monitor (4 Voice) for PET 29.90 

SPECIAL— KL-4M with Visible Music Monitor 59.90 

MICROTHELL0 for PET by Michael Riley $9.95 
Machine language version— you can't win at Level 5. 



PAPER MATE 60 Command PETWord Processor 
Full-featured version by Michael Riley 



$29.95 



Products 1 5% OFF 



All Book and Software Prices are Discounted 

PET Personal Computer Guide (Osborne) $1 2.75 

PET and the IEEE-488 Bus (Osborne) 12.75 

6502 Assembly Language (Osborne) 9.45 

Programming the 6502 (Zaks) 10.45 

6502 Applications Book (Zaks) 10.45 

Programming a Microcomputer: 6502 7.75 

6502 Software Bookbook (Scelbi) 9.45 



WRITE FOR CATALOG 

Add $1 per order for shipping. We pay balance 
ot UPS surface charges on all prepaid orders. 



>i 



CALIFORNIA COMPUTER SYSTEMS 
16K RAM BOARD. Fully buffered addressable in 4K 
blocks. IEEE standard for bank addressing 2114's. 

PCBD $27.95 Kit 450 NSEC .. .$249.95 

PT-1 PROTO BOARD. Over 2,600 holes 4" regula- 
tors. All S-100 buss functions labeled, gold fingers. 
PCBD $26.95 

PT-2 PROTO BOARD. Similar to PT-1 except set- 
up to handle solder tail sockets. PCBD ...$26.95 

CCS MAIN FRAME. Kit (S-100) $339.95 

APPLE EXTENDER. Kit $22.95 

APPLE IEEE INSTRUMENTATION INTERFACE 
KIT 7490. Kit $275.00 

ARITHMETIC PROCESSOR FOR APPLE 7811 A. 
Kit $350.00 

APPLE ASYNCHRONOUS SERIAL INTERFACE 
7710A. Kit $89.95 

APPLE SYNCHRONOUS SERIAL INTERFACE 

7712A. Kit $89.95 

ALL OTHER CCS PRODUCTS AVAILABLE 



==i7? 



PB-1 2708 & 2716 Programming Board with pro- 
visions for 4K or 8K EPROM. No external supplies 
required. Textool sockets. Kit $129.95 

CB-1A 8080 Processor Board. 2K of PROM 256 
BYTE RAM power on/rest Vector Jump Parallel 

port with status. Kit ....$129.95 PCBD $27.95 

VB-3 80 x 55 VIDEO BOARD. Graphics included, 

2 MHZ $294.95 4 MHZ $329.95 

10-4 Two serial I/O ports with full handshaking 
20/60 ma current loop: Two parallel I/O ports. 
Kit $130.00 PCBD $27.95 

VB-1B 64 x 16 video board, upper lower case Greek 
composite and parallel video with software, S-100. 
Kit $125.00 PCBD $27.95 

CB-2 Z80 CPU BOARD. Kit $185.95 

AIO APPLE SERIAL/PARALLEL $125.95 

ALL OTHER SSM PRODUCTS AVAILABLE 



W777C 



inc. WAMECO INC. 

FDC-1 FLOPPY CONTROLLER BOARD will drive 
shugart, pertek, remic 5" & 8" drives up to 8 drives, 
on board PROM with power boot up, will operate 

with CPM™ (not included). PCBD $42.95 

FPB-1 Front Panel. IMSAI size, hex displays. Byte, 

or instruction single step. PCBD $47.50 

MEM-1A 8Kx8 fully buffered, S-100, uses 2102 

type rams. PCBD $25.95 

QM-12 MOTHER BOARD, 13 slot, terminated, S-100 

board only $38.95 

CPU-1 8080A Processor board S-100 with 8 level 

vector interrupt. PCBD $27.95 

RTC-1 Realtime clock board. Two independent in- 
terrupts. Software programmable. PCBD $24.95 

EPM-1 1702A 4K Eprom card. PCBD $25.95 

EPM-2 2708/2716 16K/32K EPROM CARD. 

PCBD S25.95 

O.M-9 MOTHER BOARD. Short Version of QM-12. 

9 Slots. PCBD $32.95 

MEM-2 16Kx8 Fully Buffered 2114 Board. 

PCBD $27.95 

PTB-1 POWER SUPPLY AND TERMINATOR BOARD. 

PCBD $27.95 

IOB-1 SERIAL AND PARALLEL INTERFACE. 
2 parallel, one serial and cassette. 

PCBD $27.95 

2708 $ 9.49 2114L 450 NSEC $5.99 

2716 $35.95 2114L 200 NSEC $6.99 



m 




(415) 726-7593 
P. O. Box 955 • El Granada, CA 94018 

Please send for IC, Xistor and Computer parts list 



AUG. SPECIAL SALE 
ON PREPAID ORDERS 

(Charge cards nol included on this otter) 

WAMECO BARE PCBD SALE. 10% OFF THE 

PRICE OF WAMECO PCBD WHEN 5 OR 
MORE ARE PURCHASED. 

MIKOS PARTS ASSORTMENT 
WITH WAMECO AND CYBERCOM PCBDS 
MEM-2 with MIKOS =7 16K ram 

With L2114 450 NSEC $249.95 

MEM-2 with MIKOS =13 16K ram 

with L2114 250 NSEC $279.95 

CPU-1 with MIKOS -'2 8080A CPU $ 94.95 

QM-12 with MIKOS -4 13 slot mother 

board ...$ 95.95 

RTC-1 with MIKOS "5 real time clock $ 59.95 

EMP-1 with MIKOS =10 4K 1702 less 

EPROMS $ 49.95 

EPM-2 with MIKOS =11 16-32K EPROMS 

less EPROMS $ 59.95 

QM-9 with MIKOS =12 9 slot mother 

board S 89.95 

FPB-1 with MIKOS =14 all parts 

for front panel $144.95 

MIKOS PARTS ASSORTMENTS ARE ALL FACTORY MARKED 
PARTS. KITS INCLUDE ALL PARTS LISTED AS REQUIRED 
FOR THE COMPLETE KIT LESS PARTS LISTED. ALL SOCK- 
ETS INCLUDED. 

LARGE SELECTION OF LS TTL AVAILABLE 



VISA or MASTEHCHARGE. Send account number, interbank num. 
ber, expiration date and sign your order. Appiox. postage will 
be added. Check or money order will be sent post paid in U.S. 
If you are not a regular customer, please use charge, cashier's 
check or postal money order. Otherwise there will be a two- 
week delay for checks to clear. Calif, residents add 6% tax. 
Money back 30-day guarantee. We cannot accept returned IC's 
that have been soldered to. Prices subject to change without 
notice. 510 minimum order. $1.50 service charge on orders 
less than 510.00. 



278 BYTE August 1980 



Circle 241 on inquiry card. 



WE WILL NOT BE UNDERSOLD 



16K MEMORY UPGRADE KITS 

for TRS-80*, Apple II, Sorcerer (specify) 

PRINTERS 



$54 




NEC Spinwriter 

Letter Quality High Speed Printer 

Includes TRS-80* interface software, quick 
change print fonts, 55 cps, bidirectional, 
high resolution plotting, graphing, propor- 
tional spacing $2689 
With Tractor Feed $2889 

DIABLO 1 650 R.O. $2890 

779 CENTRONICS TRACTOR FEED PRINTER 

Same as Radio Shack line printer I 
737 CENTRONICS FRICTION & PIN FEED PRINTER 

9x7 matrix 
730 CENTRONICS FRICTION & PIN FEED PRINTER 

7x7 matrix Same as Radio Shack line printer II 
P1 CENTRONICS PRINTER 

Same as Radio Shack quick printer 
PAPER TIGER (I P440) 

Includes 2K buffer and graphics option 
TI-810 Faster than Radio Shack line printer III 

Parallel and serial w/TRS-80* interface software 
with upper and lower case and paper tray 
OKIDATA Microline 80 Friction and pin feed 

Tractor Feed, friction, and pin feed 
EATON LRC 7000 + 64 columns, plain paper 
ANADEX DP-9500 



KSR $3285 
$969 

$839 

$639 



CAT MODEM Originate and answer same as 

Radio Shack Telephone Interface II 
LEEDEX MONITOR Video 100 



$939 



$1575 

$1665 

$559 

$679 

$349 

$1389 



$148 
$129 




DISK DRIVES 



$314 



More capacity than Radio Shack 35 Track (80 K 
Bytes) drives. Fully assembled and tested. 
Ready to plug-in and run the moment you 
receive it. Can be intermixed with each other 
and Radio Shack drive on same cable. TRS-80* 
compatible silver enclosure. 
90 DAY WARRANTY. ONE YEAR ON POWER SUPPLY. 
FOR TRS-80* 

5V4", 40 Track (102K Bytes) for Model I $314 

5 Vi", 77 Track (197K Bytes) for Model I $549 

8" Drive for Model II (V 2 Meg Bytes) $795 



CCI-100 

CCI-200 
CCI-800 
For Zenith Z89 

CCI-189 
Z-87 



5Vt", 40 Track (102K Bytes) add-on drive $394 

Dual 5 Va" add-on drive system $995 

DISKETTES — Box of 10 (5 'A")- yyjth plastic library case $24.95 

8" double density for Model II (box of 10) $36.49 



$269 COMPLETE SYSTEMS 



TRS-80* LEVEL II-16K with keypad 

TRS-80* Expansion Interface 

ZENITH Z89, 48K all-in-one computer 

ZENITH Z19 

TELEVIDEO 912B $745 

ATARI 400 $489 ATARI 800 $799 

MATTEL INTELLIVISION 

NORTH STAR Horizon 1 32K, Double Density 

DISK OPERATING SYSTEMS 

PATCHPAK #4 by Percom Data 

CP/M for Model I, Zenith $145 • for Model II, Altos 

NEWDOS Plus — with over 200 modifications 35track 

and corrections to TRS-DOS 40 or 70 Track 



$719 

$269 

$2595 

$740 

920B $769 

TI99/4 $894 

$249 

$2129 



$ 8.95 
$169.00 
$ 89.00 
$ 99.00 



SOFTWARE FOR THE TRS-80* 3E=,/KX- 



CP/M BASED SOFTWARE for 
Zenith, Altos, Radio Shack, Apple 3::,/:,:" 



CCMNVESTMENT PORTFOLIO MANAGER: This is 
what investors have been wailing (or! This powerful 
program was developed by security analysts working 
with software designers. It comes on one cassette — 
16K LEVEL II BASIC on one side, 32K DISK BASIC on 
the other. Store and report data; Review your portfolio; 
Produce detailed status, value, gain, and security 
analysis; Compare alternatives $49.95/510 

INTELLIGENT TERMINAL SYSTEM ST-80III BY 
LANCE MIKLUS: Enables a TRS-80' to act as a dial- 
up terminal on any standard time sharing network. 
Provides a TRS-80* with control key. ESC Key, 
Repeal Key, Rub Out Key. Break Key, full upper and 
lower case support, selectable printer output and 
program selectable transmission rates $139/510 

CCA-DATA MANAGEMENT SYSTEM: Automate your 
information processing tasks. You can create a file of 

customer information; quickly and easily add, delete 
or update records; search a file; keep a file in order of 
the value in any field; and print records and labels in 
any desired sequence or from just a part of a file. 
Requires 32K TRS-80 and one drive. $74.95/510 

CSAMAILIST SYSTEM: Creates, maintains and effi- 
ciently utilizes a name, address and telephone 
number file. 400 individual name/address entries can 
be maintained on a single density mini-floppy, and are 
manipulated directly by record number (direct access 
file method). Sorts can be performed, name + address 
combinations can be coded. Listing-directories and 
labels can be printed. A conversion facility is provided 
to convert most sequential name, address file formats 
into direct. Requires 32K TRS-80 and one drive. 

$49.95/510 



S & M SYSTEMS 

INSEQ-80™: Indexed Sequential Access Method 
(ISAM) for the TRS-80 Model I. A must for anyone writ- 
ing business programs. Eliminate wasted disk space 
from direct record processing. Split second access to 
any record. Access data records instantly via alpha/ 
numeric "key" eg. Part NR, zip code or sequentially in 
ascending key sequence. Add/modify records in any 
order. Access up to three files per program— Files 
may be spread over multiple disks. Machine language 
processing from your basic program. Utility program 
to convert direct files to INSEQ-80 format. $49.95/510 

FULLY INTERACTIVE ACCOUNTING PACKAGE: 

ISAM (INSEQ-80) based. Includes General Ledger, 
Accounts Payable, Accounts Receivable and Payroll. 
System runs "stand alone" or "co-ordinated G/L" at 
users option. Based on Osborne accounting method. 
Requires 32K, TRS-80. 2 or 3 drives. N/A CA. 

General Lodger 599/510 

Accounts Receivable $99/510 

Accounts Payable 599/510 

Payroll 599/510 

Osborne books: Req'd as additional documentation 
$20 ea 

INVENTORY Requires 32K, TRS-80, 1 drive 5125/510 
INSORT-80: Callable form BASIC via USR. Sorts "Ran- 
dom" Disk Files. "Disk" to "Disk" sort times — 350 
records in 35 sees, 1000 records in 6 minutes, 3500 
records in 12 minutes. Machine language processing. 
Up to 35 sort keys ascending /descending. Utility to 
build BASIC program. Runs under NEWDOS. 

$49.95/510 



ACCESSORIES 

HEAD CLEANING DISKETTE- Cleans drive Read/ 
Write head in 30 seconds. Diskette absorbs loose oxide 
particles, fingerprints, and other foreign particles that 
might hinder the performance of the drive head. Lasts 
at least 3 months with daily use. Specify 5V«" or8". 
$20 ea/S45 tor 3 



FLOPPY SAVER: Protection for center holes of 5%" 
floppy disks. Only 1 needed per diskette. Kit contains 
centering post, pressure tool, tough 7-mil mylar rein- 
forcing rings. Installation tools and rings for 25 
diskettes. $11.95 

Re-orders of rings only: S 7.95 



MICROSOFT 

BASIC-80: Disk Extended BASIC ANSI compatible 
with long variable names, WHILE/WEND, chaining, 
variable length file records. $325/525 

BASIC COMPILER: Language compatible with BASIC- 
80 and 3-10 times faster execution. Produces standard 
Microsoft relocatable binary output. Includes M ACRO- 
80 Also linkable to FORTRAN-80 or COBOL-80 code 
modules. S350/S25 

FORTRAN-80: ANSI 66 (except for COMPLEX) plus 
many extensions. Includes relocatable object com- 
piler, linking loader, library with manager. Also 
includes MACRO-80 (see below) $425/525 

COBAL-80: Level 1 ANSI 74 standard COBAL plus 
most of Level 2. Full sequential, relative and indexed 
file support with variable file names. STRING, UN- 
STRING, COMPUTE, VARYING/UNTIL. EXTEND. 
CALL. COPY, SEARCH. 3-dimensional arrays, com- 
pound and abbreviated conditions, nested IF. Power- 
ful interactive screen-handling extensions. Includes 
compatible assembler, linking loader, and relocatable 
library manager as described under MACRO-80. 

$700/$25 
Z-80 SOFTCARD FOR APPLE Your key to future soft- 
ware expansion. Get the best of both worlds, Apple's 
6502 and CP/M Z-80. Plug in the card and get a Z80. 
Supports Apple language card and all Apple peripher- 
als. Comes with set of three manuals. $339/575 



CCI-TELNET VERSION 5: A communication Package 
which enables microcomputer users to communicate 
both with Large Mainframes and other microcom- 
puters. Extensive commands make it useful in many 
applications where communication between com- 
puters is necessary. Powerful terminal mode enabling 
user to save all data from a session on disk- Com- 
pletely CP/M compatible. Multiple communication 
protocols supported. Able to transfer files in both 
directions without protocol where the other machine 
does not support any protocol. Extensive ON- 
SCREEN help. Source code provided. $149/515 



MICROPRO-WORD-STAR: Menu driven visual word 
processing system for use with standard terminals 
Text formatting performed on screen. Facilities for text 
paginate, page number, justify, center and underscore. 
User can print one document while simultaneously 
editing a second. Edit facilities include global search 
and replace. Read/Write to other text files, block 
move. etc. Requires CRT terminal with addressable 
cursor positioning. 5399 /$40 

BDS 'C COMPILER: Supports most features of lan- 
guage, including structures, arrays, pointers, recursive 
function evaluation, and overlays. Package contains: 
compiler, linker, library manager; sample source files 
include games, a terminal emulator with disk I/O plus 
the source for many standard library tunctlons; BOS C 
User's Guide; Book - The C Programming Language by 
Dennis Ritchie and Brian Kernigham. Requires at least 
24KofRAM $125/520 

CONRGURABLE BUSINESS SYSTEM BY DMA: CBS 
is a data management system that allows true trans- 
action processing. Custom accounting systems for 
payables, receivables, inventory control, order, entry 
and general ledger can be set up without using any pro- 
gramming languages. CBS can be used to define an 
application such as an inventory control system by 
specifying master files to describe the inventory, cus- 
tomer and vendor files. Transaction files can then be 
used to describe activities such as purchases and 
sales. An extremely easy-to-use data entry program is 
used to enter information about customers, vendors, 
inventory, sales and purchases. After data entry is com- 
plete, an update program can process the transactions 
against the various master files, updating account 
balances and inventory quantities. The system features 
a screen menu generator and a comprehensive report 
generator which can be used to produce invoices, pur- 
chase orders, re-order reports, mailing labels or other 
special reports specific to the application. Good docu- 
mentation and a demonstration inventory system sup- 
plied. Requires at least 48K memory. Does not require 
any support language. $295 



dealer (national/international) inquiries invited Send for FREE Catalogue 



The CPU SHOP 

TO ORDER CALL TOLL FREE 1-800-343-6522 

Massachusetts residents call (617)242-3361 
For detailed technical information, call 617/242-3361 
Hours: 10AM-6PM (EST) M-F(Sat. till 5) 
"TRS-80 is a Tandy Corporation Trademark 



5 Dexter Row, Dept. B8M 
Charlestown, Massachusetts 02129 

Massachusetts residents add 
5% sales tax 

Quantities on some items are limited 




Circle 242 on inquiry card. 



BYTE August 1980 279 



Circle 243 on inquiry card. 



"State of the art" 
theDG-80Z80CPU! 



THE leading edge of 
technology for the 
Heath® H8 




DG-80 CPU 



$249 



MANUAL ONLY $25 



16K CHIP SETS (8-4116 Type Dynamic RAMS) for 
DG-32D, Apple®, TRS-80®, H88/89* and Pet® 

(Tested) $ 64.00 

32K/DG-32D $479.00 

HALF POPULATED 16K/DG-32D $415.00 

Documentation only (DG-32D) $ 12.00 



FEATURES 

• Compatible with Heath • H8 hardware and software 

• Z80 CPU — Enhanced instruction set 

• Provisions for up to 8K ROM/EPROM and/or 4K RAM 

• Jump-On-Reset to any 1 K boundary 

• Operational up to 4 MHz (2.048 MHz standard) 

• DIP switch selectable wait states for any or all 8K blocks of memory 

• All Z80 interrupt response modes available 

• Interrupt Acknowledge and Dynamic Memory Refresh signals avail- 
able on bus 

• Frequently selected options by DIP switch or solderless jumper 

• Machined contact gold sockets for ROM/EPROM, RAM 

• Includes many advanced features for future expansion 

• Assembled, tested and guaranteed 

• Extensive operations manual and Z80 PROGRAMMING MANUAL 

The DG-80 Z80 CPU is the "State of the art" CPU for the Heath® H8. The power of 
a Z80, coupled with the flexibility designed into every DG-80, lets your imagina- 
tion set the limits in possible applications with this board. 

The DG-80 Z80 CPU maintains compatibility of your current system hardware 
and software but provides features and flexibility for future expansion. Some of 
the advanced features include on-board RAM, ROM, and EPROM capability, 
jump-on-reset to any 1K boundary, and operational speeds up to 4 MHz. The 
DG-80 affords the user a superior alternative to the 8080A. 

Write or call for complete product information. 



Heath, H8, TRS-80, Apple, Mostek & Pet are Registered Trademarks. 



CMS 



ELECTRONIC 
DEVELOPMENTS CO. 



Ordering Information: Products listed available from D-G Electronic Develop- 
ments Co., P.O.Box 1124, 1827 South Armstrong, Oenison, Tx. 75020. 
Check, Money Order, VISA or Master Charge accepted. Phone orders 
(charge only) call (214) 465-7805. No COD's. Freight prepaid. Allow 3 
weeks for personal checks to clear. Texas residents add 5%. Foreign 
orders add 30%. 



M 




TRS-80's 



DISCOUNTS of 10%, 15% and More 
available. 

WE PAY Domestic U.P.S. shipping and 
insurance on minimum orders. 

NO TAXES are collected on out-of-state 
shipments. 

TOLL FREE Order Number 800/531 -7466. 

OPEN 8:00 a.m. to 6:00 p.m., Central 
Time, Monday through Friday; 
9:00 a.m. to 6:00 p.m., Saturday. 



Pan American Electronics 



Incorporated 

a Radio /haek 

AUTHORIZED SALES CENTER 

1117 CONWAY MISSION, TEXAS 78572 

TOLL FREE ORDER NUMBER 800/531-7466 

TEXAS AND PRINCIPAL TELEPHONE NUMBER 512/581-2765 



Hgg 



280 BYTE August 1980 



Circle 244 on inquiry card. 



*» 



Now a complete OHIO SCIENTIFIC 
mini-floppy system for just $797! 



Here's what you get: 



lifted* 6 * 11 --"- 



Ohio Scientific Superboard II 

The first complete computer system on a board! Includes 

keyboard, video interface and audio cassette interface. SK 

BASIC-in-R0M,4KRAM. 

Requires power supply of + 5V @ 3 amps 



$299 



fi i V 



•ell- 



_ ;«. K » * " 



"We heartily recommend Superboard II for the 
beginner who wants to get into microcomputers 
with a minimum cost. A real computer with full 
expandability." 

—POPULAR ELECTRONICS, MARCH, 1979 

"The Superboard II is an excellent choice for the 
personal computer enthusiast on a budget." 

—BYTE, MAY, 1 979 



Buy OHIO SCIENTIFIC^ 610 Expander Board and 
get $99 off reg. $299 price of mini-floppy disk drive 
[including connector cable]. ONLY $200! 




610 Expander Board 

For use with Superboard II and Challenger 1 P. 8K static RAM 
expandable to 24K or 32K system total. Accepts up to two 
mini-floppy disk drives. 
Requires +5V@4.5amps 



$298 



Mini-Floppy Disk Drive 

Includes Ohio Scientific's PICO DOS software and connector 
cable. Compatible with 61 Expander Board. 
Requires + 1 2V @ 1 .5 amps and + 5V @ 0.7 amps. 

Reg. $299 SALE! $200 

TOTAL S797 



79 



4KP 4K RAM chip set S 

PS003 Mini-floppy power supply 

each S 
PS005 5V 4.5 amp open frame 
power supply S 

SAMS manual C1 P/Superboard II S 
SAMS manual C4P S 

0S-65D V3.2 Disk Operating System 
with 9-digit extended BASIC, random 
access from sequential files S 

C4P computer 8K RAM expandable 
to 32K RAM S 

C4P MF computer Mini-floppy, 
S4K RAM S1795 

C8P computer 8K RAM expandable 
to 32K and dual 8-inch floppies S 950 

C8P DF computer 32K RAM 
expandable to 48K, dual 8-inch 
floppies S2895 



29 

35 

8 
16 



49 



750 



NEW! SAMS manual for the 
Challenger III Series 5 40 



Attention Superboard II and C1P owners: 

You can still take advantage of our summer sale. Purchase the 61 
Expander Board for the regular price and get £99 off on the mini-floppy 
and cable. 
Step up to mini-floppy operation for only $498. 



COMING SOON ! Color Video Adaptor for Superboard II and C1P! 



Freight Policies 

All orders of $1 00 or more are shipped 
freight prepaid. Orders of less than $1 00 
please add S4.00 to cover shipping costs. 
Ohio Residents add 5.5% Sales Tax. 

Guaranteed Shipment Cleveland 

Consumer Computers 6. Components 
guarantees shipment of computer systems 
within 48 hours upon receipt of your order. 
Our failure to ship within 48 hours 
entitles you to S35 of software, FREE. 



To Order: 

Or to get our free catalog 

CALL 1-800-321-5805 TOLL FREE. 

Charge your order to your 
VISA or MASTER CHARGE ACCOUNT 
Ohio Residents Call: [216] 464-8047. 
Or write, including your check or money 
order, to the address listed below. 

Hours: 

Call Monday thru Friday 
8:00 AM to 5:00 PM E.D.T. 



VISA 




s© 



.CLEVELAND CONSUMER 
BSSS COMPUTERS & COMPONENTS 

P.O. Box 46627 
Cleveland, Ohio 44146 



TO ORDER: CALL 

1-800-321-5805 

TOLL FREE 



Circle 245 on inquiry card. 



BYTE Augusl 1980 281 



Circle 246 on inquiry card. 



NEW & IN STOCK. 



$599. 00 



77 TRACK 
DISK DRIVES 

• 5V«" drive with power supply and enclosure. 

C-ITOH™ STARWRITER $21950° 

(DAISY WHEEL PRINTER) 



SUPERBRAIN™ - COMPUSTAR 

300 - K DISK STORAGE 64 K $2995 00 

10 Maxell Diskettes FREE WITH EVERY UNIT 



TM 



TRS-80™ 64 K MODEL II S3626.00 

IN STOCK • IMMEDIATE DELIVERY 

ORDER NOW (1) 800 345-8102 



MODEL II DISK DRIVES 

1 drive, single enclosure S 899.00 

1 drive, multiple enclosure S1069.S0 

additional drives (or multiple enclosure j 540.00 



MODEL I DISK DRIVES pertec 40 trk $340.00 

$159.00 less than Radio Shack 



EXPANSION INTERFACES 



K S278.10 



16 K $376.10 



32 K $474.10 



List Our Price 
TRS-80 4K Level II S619.00 $575.70 
TRS-80 16K Level II S849.00 $789.60 
Telephone Modem S199.00 $ 185.10 
RS 232 S 92.10 



NEC 5510 (In Stock) 
Centronics 730 
Centronics 737 
Centronics 779 Sale 



Our Price 
$2950.00 
$ 695.00 
$ 950.00 
$ 995.00 



VR DATA 

ORDER 1-800-345 8102 
NOW (215) 461-5300 



777 HENDERSON BOULEVARD 
FOICROFT INDUSTRIAL PARK ■"" 
FOLCROFT, PA 19032 £ 

Our Prices Are For Cash ^*^ 

Payment Terms. Call For Other Terms. 



V R DATA'S TRS-80™ 
SWEEPSTAKES 

Celebrating V. R. DATA's 8th Anniversary 

OVER $1700.00 in PRIZES 
GRAND PRIZE- 16 K Lll TRS-80 

TWO SECOND PRIZES - DISK DRIVES 

FOUR THIRD PRIZES — *50.°° g.ft certificates 

SWEEPSTAKES RULES 

1 ALL ENTRIES MUST BE SUBMITTED ON 
ORIGINAL ENTRY BLANK. 

2. ONE ENTRY PER PERSON. 

3. WINNERS SELECTED BY RANDOM DRAWING, 
NOTIFIED BY MAIL. 

4. ENTRIES MUST BE RECEIVED BY 10/31/80. 

5. VOID WHERE PROHIBITED BY LAW, 
NO PURCHASE NECESSARY. 



MAIL NOW TO 

NAME 


ENTER 


V. R. DATA'S 


SWEEPSTAKES 


ADDRESS 


CITY 

TELEPHONE 
COMPUTER 


EQUIPMENT OWNEt 


..STATE 

OCCUPATION 
) 


...ZIP 










INTENDED ISE 












B 


SEND 


FOR 


CATALOG 


□ 




Dual Trace Oscilloscope 



HITACHI 30 MHz 

• TV sync-separater circuit 

• High-sensitivity 1mV/div 
(5MHz) 

• Sweep-time magnifier 
(10 times) 

• Z-axis input (Intensity 
modulation) 

• Signal delay line 

• X-Y operation 

• Trace Rotation 



$945.00 

More sensitive to your input 



SD SYSTEMS 




Z-80 



STARTER 
SYSTEM 



The Z80 Starter Kit by SD Systems 
uses the powerful Z80 microproces- 
sor as the heart of the complete micro- 
computer on a single board. Learn a 
sfl& i-^WH Hl Yl'.n step-bystep introduction to micro- 
computers with a keyboard and display, audio cassette inter- 
face, PROM programmer, wire-wrap expansion area, 4- 
channel Counter Timer and on Board RAM and PROM. 
Complete Opperation and Instruction Manual included. ZBUG 
Monitor in ROM. 

27004 kit $340 38007 a/t $450 




SBC-1 00 BOARD 

COMPUTER KIT 

27003 kit $295 



PROM Programmer 
27014 kit S200 



LOOK - MORE SDC 



VERSAFLOPPY I 

FLEXIBLE DISK 

DRIVE Controller 




27002 kit S250 

38005 a/t S335 



VDB-8024 

VIDEO 

DISPLAY BOARD 




8080A 



MICRO- 
PROCESSOR 



:95 



AP PRODUCTS 



923101 . S 79.95 

923102 . . 124.95 
103. . 124 95 



O PLESSEY 




SD Systems 
EXPANDO RAM 




27001 kit $220 

38001 a/t $480 



Add-On RAM Kit 

27010 (lGK.edov, ( :u.,) $165 



FUNCTION GENERATOR KIT 
XR2206KB 




NEW 

HICKOK 

LX304 



DIGITAL 
MULTIMETER 




ALSO - STILL AVAILABLE 

LX303 $74-95 



\v <"'H 



32K 

Part No. DP1000-2 

$1295 



32K HAM 

DiiinxJ Clur 
Eda> card 



LIQUID CRYSTAL DISPLAY 

F". n.'n'fl' * Hit J h Contrast Ratio 
I + i,Dju,U * Wide Viewing Angle 
hnQQOHIBn • 0.5 in. Digit Height 
• ULTRA Low Power Consumption 
LCD10G $14.50 



SYM-t 



NEW LOW 
PRICE 




$239.00 

KTM-2 CHT/TV Kybd Term S349 



EPROM 

2708 $ 10 50 



EPROM 

5 29 9C 



(5 Volt) 

2716 



POWER SUPPLY 

5 Volt 3 Amp 
APS 5-3 

S42.50 
$40.66 
$38.85 




* 1 5% * 

DISCOUNT 

COUPON 

Bring this I O I l*OA" into one ofourstoresor 

mail to our Mail Order address shown below and 

receive a 15% IIISIOIXT 

on purchases from this Ad of £1 00.00 or more. 

Offer i: V IMIUS on Aii^tisl :t I . I 9MIO 

NAME 

ADDRESS 

CITY STATE 

ZIP PHONE NO 

Coupons accepted only wilh full name and address filled in 



® 



Send check or Mane 
California residents 
Add SI 00 10 cover postage and h 
Please include you' charge card nu 
Interbank number and expiration 



i Ortlei iii P flu. Z2DBY Culvm City CA 90230 
add 6% sales la* Minimum Oidi-i $10 00 
ig Master Charge and Visa welcomed 

PHONE ORDERS: [213} 641-4064 



MAIL ORDER 

PO Box 2208R 

ilrvei Oiv.CA 90230 

1213) 641-4064 



TUCSON 



PORTLAND 



15031 254-5641 



HOUSTON 



1713) 529-3489 



14041 261 7100 



CULVER CITY 



'713) 39&3S95 



SUNNYVALE 



MORI 243-4171 



282 BYTE August 1980 



Circle 247 on inquiry card. 



DIGITAL RESEARCH COMPUTERS 

(214)271-3538 



32K S-100 EPROM CARD 





USES 2716s 

Blank PC Board - $34 

ASSEMBLED & TESTED 
ADD S30 

SPECIAL: 2716 EPROM's (450 NS) Are S19.95 EA. With Above Kit. 



KIT FEATURES 

1 Uses +5V only 2716 (2Kx8) EPROM's 

2 Allows up to 32K of software on line! 
3. IEEE S-100 Compatible. 

4 Addressable as two independent 16K 

blocks. 
5. Cromemco extended or Northstar bank 

select 
6 On board wait state circuitry if needed. 



7 Any or all EPROM locations can be 

disabled. 
8. Double sided PC board, solder-masked. 

silk-screened 
9 Gold plated contact fingers. 

10. Unselected EPROM's automatically 
powered down for low power 

11. Fully buffered and bypassed. 

12. Easy and quick to assemble. 



8K LOW POWER RAM KIT-S 100 BUSS 



21L02 
(450 NS RAMS!) 



.•&X :■'■% '"■" IPa* (f 'iM lt-af t niiri -JUt 



$ 1 1 9 5 K ? T 



ASSEMBLED & FULLY 
BURNED IN ADD S35 



Thousands of computer systems rely on this rugged, work horse. RAM 

board Designed for error-free. NO HASSLE, systems use 

Blank PC Board w/Documentation - $29.95 

Low Profile Socket Set - S13.50 

Support IC's (TTL & Regulators) - S9.75 

Bypass CAP's (Disc & Tantalums) - $4.50 



ADD S10 
FOR 4 MHZ 



FOR 
4MHZ 



sM- el 



LOW POWER - 300NS 8 FOR 

2114 RAM SALE! *4« 

4K STATIC RAM'S. MAJOR BRAND, NEW PARTS. 

These are the most sought after 21 14's, LOW POWER and 300NS FAST. 

8 FOR $44 



16K STATIC RAM KIT-S 100 BUSS 



16K STATIC RAM SS-50 BUSS 




PRICE CUT! 



*229k, t 



fi § i 1 11 Hi II 1 11 1 r 

1 1 1 1 11 iiiiiinii 



FULLY STATIC! 



KIT FEATURES 

1 Addressable as (our separate 4K Blocks. 

2 ON BOARD BANK SELECT circuitry. (Cro- 
memco Standard 1 ) Allows up to 512K on line! 
3. Uses 2114 (450NS) 4K Sialic Rams. . _... p Rn p|| cqnrKFT HFT-4H9 

4 ON BOARD SELECTABLE WAIT STATES. LOW PHUr ILL bUOKb I t>t I »1<! 

5 Double sided PC Board, with solder mask and SUPPORT IC'S & CAPS-$19 95 
silk screened layout Gold plated contact fingers 

6 All address and data lines fully buffered 

7 Kit includes ALL parts and sockets 

8 PHANTOM is jumpered to PIN 67 

9. LOW POWER: under 1 .5 amps TYPICAL Irom 
the +8 Volt Buss 

10. Blank PC Board can be populaled as any 
multiple of 4K 



FOR 2MHZ 
ADD $10 






j£3m 



BLANK PC BOARD W/DATA-$33 



ASSEMBLED & TESTED-ADD $35 



FOR SWTPC 
6800 BUSS! 



OUR #1 SELLING 
RAM BOARD! 



ASSEMBLED AND 
TESTED - $35 



KIT FEATURES 

' Addressable on 16K Boundaries 

2 Uses 2114 Sialic Ram 

3. Fully Bypassed 

4 Double sidec PC Board Solder mask 
and silk screened layout 

5 M Pans and Sockets included 

6 Low Powe 1 Under 1 5 Amps Typical 



BLANK PC BOARD— $26 COMPLETE SOCKET SET- 
SUPPORT IC'S AND CAPS— $19.95 



$12 



MtMM 1 - STEREO! new, 

S-100 SOUND COMPUTER BOARD 



16K EPROM CARD-S 100 BUSS 



COMPLETE KIT! 
$8495 

(WITH DATA MANUAL) 



At last, an S-100 Board mat unleashes Ihe full power of iwo 
unbelievable General Instruments A Y3-8910NMOS computer 
sound IC's Allows you under total computer control to 
generate an intinile number of special sound effects for 
games or any other program. Sounds can be called in BASIC, 
ASSEMBLY LANGUAGE, etc. 
KIT FEATURES: 

* TWO Gl SOUND COMPUTER IC'S 

* FOUR PARALLEL I/O PORTS ON BOARD 
. USES ON BOARD AUDIO AMPS OR YOUR STEREO 

* ON BOARD PROTO TYPING AREA. 

* ALL SOCKETS. PARTS AND HARDWARE ARE INCLUDED 
» PC BOARD IS SOLDERMASKED, SILK SCREENED. WITH GOLD CONTACTS 

* EASY. QUICK. AND FUN TO BUILD WITH FULL INSTRUCTIONS 

* USES PROGRAMMED I/O FOR MAXIMUM SYSTEM FLEXIBILITY 
Both Basic and Assembly Language Programming examples are included 

SOFTWARE: 
SCL'" is now availahle' Our Sound Command Language makes writing Sound Effects programs 
a SNAP 1 SCL'" also includes routines lor Register Examine- Modify Memory-Examine-Modify 
and Play-Memory SCL'" is available on CP M" compatible diskelle of 2708 or 2716 Diskelle 
$24.95 2708 - S19.95 2716 - S29.95 Diskette includes the source EPROM S are ORG at 
E000H 



BLANK PC 

BOARD W/DATA 

$31 




USES 2708s! 



nrrrnt 



Thousands of personal ana business systems around Ihe world use this board with 
complete satisfaclion. Puts 16K of software no line at ALL TIMES' Kit features a top 
quality soldermasked and silk-screened PC board and firs' run parts and sockets Any 
number of EPROM locations may be disabled to avoid any memory conflicts Fully 
buffeied and has WAIT STATE capabilities 



ASSEMBLED AND FULLY 
TESTED — ADD $30 



OUR 450 NS 2708'S 
ARE $8.95 EA. WITH 
PURCHASE OF KIT 



RCA CMOS COMPUTER CHIP SET 

INCLUDES: 

1-CDP1802CD CPU 1-CDP1861CD VIDEO IC 

2-CDP1822CE 256 x 4 RAM 1-CDP1862CE COLOR GEN. 

1-CDP1858CE 4 BIT LATCH 1-CDP1863CE SOUND GEN. 
COMPLETE SET $45 limited qty 



NEW! G.I. COMPUTER SOUND CHIP 

AY3-B910 As featured in July. 1979 BYTE 1 A fantastically powerful Sound & Music 
Generator Perfect lor use with any 8 Bit Micropiocessoi Contains 3Tono Channels 
Noise Generaloi. 3 Channels of Amplitude Contiol 16 hi I Envelope Per lOdConliol. 2-8 
Bit Parallel I/O 3 Dto A Converters, plus much more' All in one 40 Pin DIP Supet easy 
interface to Ihe S-100 or other busses 
SPECIAL OFFER: $14.95 each Add $3 for 60 page Data Manuai. 



Digital Research Computers 

** (OF TEXAS) ' 

P.O. BOX 401565 • GARLAND, TEXAS 75040 • (214)271-3538 



TERMS: Add Si. 00 postage we pay halation OideiS undet $15 add 75C 
handling No C O D We accept Visa and MasteiChaige Tex Res add ?°o 
Tax Foreign orders (excepl Canadat add ?0°k P & H 90 Day Money Baek 
Guarantee on all items. Orders ovet $50. add 85C for insurance. 



•TRADEMARK OF DIGITAL RESEARCH. 

Circle 248 on inquiry card. 



NOT ASSOCIATED WITH DIGITAL RESEARCH OF CALIFORNIA. THE SUPPLIERS OF CPM SOFTWARE. 

BYTE August 1980 283 



Circle 249 on inquiry card 




32K *1050 48K M125 



APPLE II OR APPLE II PLUS 



J-L. 



The APPLE II is a completely assembled and tested computer 
system. The system includes a rugged molded case, typewriter- 
style keyboard with N-key rollover, high-efficiency switching 
power supply, two hand controllers, demonstration programs on 
tape cassettes, AC power cord, cassette cable, reference 
manuals. 



APPLE II has ROM-resident Integer BASIC interpreter, monitor, 
mini -assembler and disassembler & BASIC Programming Manual 

APPLE II PLUS has ROM-resident Applesoft Extended BASIC 
interpreter, Auto-Start ROM, disassembler & Applesoft Tutorial 
Manual 



DISK ll-DRIVE ONLY 


J429 


PROGRAMMABLE TIMER MODULE 




MSRSUPR-IERMINAL 80 COLUMN 




DISK II DRIVE S CONTROLLER CARD 


(89 


No. )440A 


145 


BOARD 


.in 


MODEM I1BWJ INTERFACE 


339 


3". DIGIT BCOANALOGTO 




MICROSOFT Z-80 SOFTCARD SYS1LM 




MODEM MB ONLY (Novation Cat) 


159 


DITIGAL CONVERTER 


135 


WrCP/M 


299 


GRAPHICS TABLET.. .. 


659 


GPIB IEEE-488 (19781 INTLRTACE 




HICROWORHS DS-65 DIGISECT0R 


339 






No 7490A. . . 


259 


MOUNTAIN HARDWARE 




SILENTYPE PRINTER 




ASYNCHRONOUS SERIAL IN1ER1AC 




APPLE CLOCK 'CALENDER CARD 


229 


W/Apple Intelace 


519 


No 77IOA 


145 


SUPERTALHER SPEECH SYN1HISI2ER 




APPLE COMPUTER 




SYNCHRONOUS SERIAL INTERf ACE 




SYSTEM 


249 










TOMPLUS-«'KIYB0AHIIIIUIR 


169 


PROTOTYPING/HOBBY CARD 


$22 






R0MPLUS- wo/KEYBOARD FILTER 


165 










NIROL X-10 REMOTE CONTROL 












SYSTEM 


249 


Connector Cable 








INTR0L X 10 CONTROLLER ONLY 


169 


Hl-SPEED SERIAL INTERFACE CARD 


155 






ROMWRITER SYSTEM 


159 


LANGUAGE SYSTEM WITH PASCAL 


429 






PROGRAMMAAPPLF JOYSTICK 


39 


CENTRONICS PRINTER 




PCB ETCH BOARD 


20 


SEE THRU CLEAR PLASTIC TOP 




INTERFACE CARD 


185 


CORVUS 




FOR APPLE II 


23 


APPLESOFT II FIRMWARE CARD 




CORVUS ID MEGABYTE HARD DISK 




SSMA10SERIAL PARALLEL 10 




W/Auto-Start ROM . . 


149 


DRIVE SYSTEM . 


S4495 


CARD (KID 


129 


INTEGER BASIC FIRMWARE CARD 




CORVUS MIRR0R1 (VTR Required) 


695 


SSMA10 ASSEMBLED S TESTED 


169 


W/Mon. & Prog. Aid ROMS 


149 


CORVUS MIRR0R2 (VIH Required) 


795 


SYMTEC 




ADD-ONS 




CORVUS CONSTELLATION 


595 


APPLE LIGH1 PEN SVS11M 


219 


!6K MEMORY UPGRADE 




DAN PAYMAR LOWER CASE ADAPTER 44 


SUPER SOUND GENERAI0R (MONO) 


139 


(TRS-80, Apple Sorcerer). . 


169 


DCHAYESMICROMODEMII 


319 


SUPER SOUND GENERAlORiSIEREOI 


m 


ABT NUMERIC INPUT KEYPAD 




HUERISTICS 




SVA 8 INCH DISK DRIVE CONIR0LLER 




(Old or New Kybrd) . ... 


119 


SPEECHLINK 2000(64 Word 








ALF MUSIC SYNTH'SIZER . . 


239 


Vocabulary) 


219 


VERSA WRITER 0IGIII2ER DRAWING 




ALF TIMING MODE INPUT BOARD 


19 


SPEECHLAB 20A ICasselle) 


169 






BRIGHTPEN LIGHTPEN Irom SOFTAPE 


32 


SPEECHLAB 20A (Diskette) 


189 




119 


I?K ROM/PROM ASSEMBLED 


MODEL 70 CONTROLLER 
MiRSUP-R.MODTVMODULAlOR 


75 


VIDEXVIDEOTEBM W GRAPHICS 
[PROM 


339 


BOARD NO. 71 MA 


569 


ADAPTFR 




|r m "1| ORDERING INFORMATION:^ 1 ' 1 '" orders may be pi 


iced using 


' 


1 




i.iiiow 2 weeks lo clear) Please 


tiers n 

cashier 

iclude t 


v.s,i, MiiHioriiiirt] or 




VISA 


i^4 








S4 


Check, money order or porsc 

tlephone number with all orders 


nal check 1 

Foreign orci. 


1 


rs (exclud 






Military PO'BJ add IO°u for shipping an 


1 funds must be in U S dollar 


5 Shipping, 


widltng < 


net - ^ m 


■v 


insurance in U S is r»Oc ne 


It) SU 


face. Si 00 ner lb lor air 


No CODs 









APPLE IU APPLE II PLUS 
SOFTWARE 

PASCAL with LANGUAGE SYSIEM J429 
FORTRAN tor use with LANGUAGE 

SYSTEM 169 
CP/M tor use with MICROSOFT 2-80 

SOFTCARD .... 299 
THE CONTROLLER General Business 

System 519 
1HE CASHIER Retail Maiiageineiil & 

Inventory 199 

APPLLWRITER Word Processor 65 

APPLEPOST Marling lisl System 45 

APPLLP0ST Graph & Plot System 85 

DOW I0NES PORTFOLIO EVALUATOH 45 
CONTRIBUTED VOLUMES 1 IHRU 5 

*, MANUALS 35 

VISI-CALC by PERSONAL S0F1WARE 125 
DESKTOP. PLAN by DESKTOP 

COMPUTERS 85 
CCA DATA MANAGEMFNT 

By PERSONAL SOFTWARE 85 
PIMS Personal In formation 

Management System 23 

ADVENTURE by MICROSOFT 27 

SUB-LOGIC FS-I Flight Simulate 23 

SARGON II Chess by HAYDEN (Cass) 27 

SARG0N 11 Chesson Diskette 32 

Bill Budges TRILOCY ol GAMTS 27 

Bill Budges SPACE GAME ALBUM 32 

SPACE INVADER on cassette 18 

SPACE INVADER on Diskette 23 

SYBEX APPLE SO 80SO SIMULATOR 17 



FORTH II by PR0GRAMMA SOFTWARE 
SINGLE DISK COPY ROUTINES 
APPLEBUG ASSEMBLER 

DISASSEMBLER 
APPLEBUG DEBUGGER 
APPLESOFT UTILITY PROGRAMS 

By HAYDEN 

PRINTERS, TERMINALS 
& MONITORS 

PRINTERS, TERMINALS S MONITORS 

ANADEX DP8000 or DP8000AP S 

ANADEXDP9500or0P9501 I 

BASE 2 » TRACTOR S BUFFER 

CENTRONICS 700-9 ! 

CENTRONICS 737 

MP1 88T 

PAPER TIGER IDS 440 

W GRAPHICS OPTION 

NEC SPINWRITER 5530 oi 5510 2 

TRENDC0M 100 

TRENDCOM200 

LEEDEX VIDEO 100 

SANYO 9 INCH BSW MONITOR 

SANYO 15 INCH MONITOR 

Tl U INCH COLOR MONITOR 

S0R0CIQ120 

S0ROCIQ140 1 

HA2ELTINE 1500 

HA2ELTINE 1510 1 

HA2ELTINE1520 I 

HA2EL1INE 1410 

HA2ELIINE 1420 



'WE WILL NOT BE UNDER SOLD! " 

COMPUTER SPECIALTIES 

6363 EL CAJON BLVD., SUITE 205, 
SAN DIEGO, CA. 921 IS • (71 41 5T9-0330 




TECHNOLOGY, INC. 



52 K STATIC RAID 

S-lOO MEMORY BOARD 



$49995 



FULLY STATIC OPERATION 
-IK BANK ADDRESSABLE 
EXTENDED MEMORY MGMT 
MEETS IEEE PROPOSED 
S-lOO SIGNAL STANDARDS 
4 MHZ OPERATION 



74LS193 
74LS195 
74LS196 
74LS22T 
74LS240 
74LS241 
74LS243 
74LS244 
74LS245 
74LS253 
I 74LS257 



CIRCUITS 
95 74LS258 



74LS259 
74LS279 
74LS283 
74LS293 
74LS298 
2 20 74LS366 
2 45 74LS367 
74LS368 
74LS373 
74LS374 



95 

85 

140 

2 45 

245 



6 95 



95 



95 

285 

55 

100 

185 

120 

95 

95 

95 

250 

2 50 



EPROM'S 

2708 S6.7S 

IKx8 450NS 

8 FOR S48.50 
27I6 SIB 95 

I6KI2KX8I450NS 
8 FOR SI42 95 

2732 sjjfeo 



*58.50 



32K(4096*81 



wideo 



A79 



MSM5B32 MICROPROCESSOR 
REAL-TIME 
CLOCK/CALENDAR 
GENERAL DESCRIPTION 



745 



CONCORD 

COA1PUTER 

"" componcrm 



16K Memory Add-On For 

APPLE 4750 1 
TRS-80 4995| 

MEMORY ADD-ON KIT 
INCLUDES INSTRUCTIONS. 
RAMS. AND JUMPERS 
NO TOOLS REQUIRED 

VOLTAGE REGULATORS 



NEGATIVE 
7905 1 5V J 
7908 18V I 
7915 (15V J 



7918(18V( 7812/12W 



POSITIVE 

7805(5V( 7815(15Vi 

7806/6V/ 7818118V) 

7808(8V( 7824I24VJ 



Leedex Corp 



05* 



12" BLACK & WHITE 
LOW COST VIDEO 
MONITOR 



1971 SOUTH STATE COLLEGE ANAHEIM, CA. 92806 

VISA MASTERCHARCE lltA\nV7 tflCTT MINIMUM ORDER ilfj 00 

CHECK OR M \llH)\lSr\)bSI ADDJI50FORFRT 



VISA MASTERCHARCt lyt»\nVJ tflCTT MINIMUM ORDER $1000 

CHECK OR M U«J"j'"UM/ ADO SI 50 FOR FRT 

NO COO *• s,Kk and se " o»er!2.000 typesol semi conductor!, CAl. RES ADO 6% 



* 2114L 



1024x4 Static RAM' 
450 ns 



$450 



284 BYTE August 1980 



Circle 250 on inquiry card. 



HOB8YWOAID 

ELECTRONICS, INC 



Coll Toll-Free: USA (800) 423-5387 

In California: (800) 382-3651 

Local & Outside USA: (213) 886-9200 



SSM VB2 
VIDCO BOARD 

1/0 conlrolled video interface board With a TV 
monitor, Ihe VB2 becomes a video terminal 1 
No other I/O card is required for keyboard in- 
put and video display The cursor, linefeed. 
carriage return, backspace and clear screen 
are hardware controlled The display is 64 X 
16, ail upper case and is selectable for white- 
on-black or black-on-white 
Produces a dear, bright display, and features 
adjustable picture size and characler width 
Circuitry is provided to drive a speaker for 
beep lone 
Cat No. Description Price 

1438 VB2 kit $169.00 

1439 VB2 A&T $234.00 



Leedex 
VIDCO 100 
12" MONITOR 




• Compatible with TRS-80 (no interface required) 

• Compatible with many home computers' 

Now Irom LEEDEX One ot the most popular low cost . ye! high res- 
olution (650 line) monitors currently available These units compare 
lavorably with monitors costing twice as much Because ot the tact 
that standard composite video input is utilized no RF modulator is 
needed An extremely sharp and stable picture is achieved The video 
bandwidth is 12 mhz + / - 3db with a 75 ohm input impedance 
Cat No. 1204 Video 100 Monitor Wt 18 lb. $149.00 

Cat No. 1937 TRS-80/Leedex cable kit Wt. 6 oz. $3.00 



Continental Specialties 
LOGIC PROBCS 



Compact and versatile. Perfect for test and trouble- 
shooting all types of digital applications! Simple to 
operate . . . just connect the clip leads to the circuits 
power supply, flip the logic switch, and test! LEDs Indi- 
cate test results and circuit conditions. Combines the 
functions of level detector, pulse detector, pulse 
stretcher, and memory. Available in three models. 

LP-1 Hand-held instant reading 
of logic levels for TTL, DTL, 
HTL or CMOS. 
Cat No. 2067 $44.00 



LP-1 Tne economy model without 
the memory capability. 
Safer than a voltmeter, more 
accurate than a scope! 
Cat No. 2068 $ 26#85 

LP-3 Faster version of the LP-1. 
High speed logic probe cap- 
tures pulses as short as 

Cat No. 2069 $69.00, 



S€ND FOR FR€€ 
FLY€R,F€flTURING: 

Page after page ot exciling products 
Computerized toys and games, per 
sonal computers, disk drives, in- 
tegrated circuits, semi conductors 
Add new dimension to your Apple. 
Atari. TRS-80. etc with our special ap- 
plication boards and comprehensive 
software library. Hundreds of pro- 
ducts available at terrific Hobbyworld 
prices Circle our reader service 
number or write/phone for your free 
illustrated tlyer today 

HOW TO ORDCR 

Pay by check. Mastsrcharge. Visa, or COD 
Charge card orders please include expiration 
date Payment in US dollars only. Order by 
phone, mail or at our retail store. MINIMUM 
ORDER 510 00 Please include phone number 
and magazine issue you are ordering Irom 
Prices valid thru last day ol cover date. SHIP- 
PING: USA: Add S2.Q0 for first 2 lbs.. 35c 
each addt I lb. (or ground For AIR add S3. 00 
tint 2 lbs.. 75c each addt lib FOREIGN: sur- 
face. 13.00 first 2 lbs.. 60c each addt 1 lb. 
AIR: Si 1 00 first 2 lbs . S5 00 each addt 'I lb 
COOs add Si 25 addt I Not responsible for 
typographical errors Some items subject to 
prior sale or quantity limitations. 120 day 
guaranteed satisfaction. Exception partially 
assembled kits 




TRS-80 CP/M 

At last, CP/M is available for the TRS-80 1 
Long a standard lor software development and 
interchange (or all the "other" 8080/Z80 
computers on the market. CP/M will now pro- 
vide the same environment for the TRS-80 
CP/M is a fife-oriented disk operating system 
thai provides a common set of utilities lor pro- 
gram development and operation There are 
six built m commands plus utilities called in 
rom disk CP/M will run on a TRS-80 with as 
ittle as 1 6k ol memory and one disk drive 
Comes complete with six manuals CP/M is a 
registered trade mark ol Digital Research 
Cat No. 1679 <1AO OK 

THS-80 Level II I6k-w/disk *■•"•» * 



:cs 

16K Static 
Ram Board 



True static RAM board designed specifically for the 
S-100 bus. Requires only +5VDC. Features true static 
operation, and all bus signals labeled on board! Uses 
2114 low power static RAS. S-100 compatible, fully buff- 
ered. Silk screened PC board, solder masked on both 
sides. 

Cat No. Description Wt Pries 

1601A 16K RAM 450ns Kit 1 lb $253.50 

1601 B 16K RAM 200ns Kit 11b $333.50 

1601C 16K RAM 300ns Kit 1 lb $293.50 

1602A 16K RAM 450ns A&T 1 lb $285.75 

1602B 16K RAM 200ns A&T 1 lb $371.50 

1602C 16K RAM 300ns A&T 1 lb $328.50 

1603 16K RAM Bareboard only 6 oz. $ 29.95 



CCS 32K Static RAM Board 
$710 

Uses 2114, 250ns fully Static Rams, bank selectable in 
8K blocks. Enable/Disable on Power up or Reset. Com- 
patible with North Star, Alpha Micro, Cromeco, etc. Also 
front panel compatible, addressable in 8K blocks. 
Selectable Wait state. Wt 1 lb. Assembled & tested. 
Cat No. 2644 



TH€ PIC 2.0 $79.95 
(Programme Improved Cditor) 

Don't be mislead by the low price of (his outstanding wordprocessing 
package PIE 2.0 is a powerful text editor and print format processor 
lhat has all the bells and whistles expected of wordprocessing soft- 
ware costing three times as much Some features include 

1) Character/line insert and delete 

2) Complete Cursor mobility 

3) String search forward and backward 

4) Single, conditional or global search and replace 

5) Move and/or copy blocks of text 

6) Page scrolling 

7) Tabs, margins, paragraphing, etc. 

Research conducted by IBM Corp. revealed that the time required to 
create, edit and complete a one page document was decreased by as 
much as 60% when comparing the performance of a Wordprocessing 
system to an ordinary typewriter Finding ways to remain competitive 
these days is a challenge lor the business executive Todays office 
can substantially improve their daily productivity level with PIE 2 
Wordprocessing software and an Apple II computer with 32k RAM 
memory. 

As a businessman you want every dollar you spend to count, so 
wordprocessing makes sense, and PIE 2.0 Wordprocessing soltware 
gives you more for your hard earned dollar. PIE 2 Wordprocessing 
soltware comes complete wi'h program diskette and detailed 
documentation in a handsome, simulated leather binder 
Cat No. 2562 




CCS 7811B 

RRITHMCTIC 

PROCCSSOA 

Assembled & tested, adds advanced arith- 
metic power to your Apple II. AMD AM 9511 
pased. 16 and 32 bit fixed point. 32 bit float- 
ng point operation. Float to fixed and fixed to 
float conversions. Trig and inverse functions, 
square roots, logs, exponentiation. Interrupt 
daisy chain. DMA daisy chain, and much 
more. Wt. 2 t"Xt*f% OK 
Cat No. 1635 # 5YY.YD 



DISKCTTC DfllV€ H€BD CURNING KIT 



Oisketle drive heads need periodic maintenance to assure efficient and error-free 
operation. Unlike other peripheral devices, the read/write head(s) on diskette 
drives are extremely difficult to clean without partially disassembling Ihe drive. 
The diskette drive head cleaning kit allows the user to clean the heads in just min- 
utes, without disassembling the drive. Available in 5Vi" or 6". both single and 
double sided. Kit contains 2 cleaning diskettes. 4 oz. bottle of CS-85 cleaning 
solution and an easy pour dispenser. 
Weight 12 oz. 

CAT NO. DESCRIPTION PRICE 

2499 8" Disk Drive Cleaning Kit S30.75 

2534 5V* - Disk Drive Cleaning Kit $30.75 



16K MCMORV 
ADD-ON KIT $55.00 

Everything you need to upgrade your 
TRS-80, Apple or Exidy! An additional 
16K includes illustrated instructions, 
RAMS and preprogrammed jumpers. No 
special tools required. Wt. 4 oz. 

CAT NO PESCRIPTION 

1156 TRS BO Keyboard Unit 

1 1 56 A TRS 80 Exp. Interlace (prior to 4/1/79) 

1 156 B TRS BO Exp. InteHacelallet 411.79) 

1 1 56 C lor Apple M 

1156D for Exidy 



VCRBRTIM 5% " DISK€TT€S 

10 per box 



CAT NO. 


TYPE 


DESCRIPTION 


PRICE 


1147 


52501 


Soli sector. TRS-80. etc. 


$33 00 


1148 


525-10 


10 hole, hard, Apple, 








North Star 


$33.00 


1149 


525 16 


16 hole, hard, Micropolis 


$33.00 


2330 


57701 


Solt sector, certllled 


$49.95 


2331 


577-10 


10 hole. hard, certified 


$49.95 


2332 


577-16 


16 hole. hard, certified 


$49.95 



The EMAKO 22 microprinter is a de- 
pendable, low cost addition for your 
personal computer system. It 
features a 9X7 dot matrix character 
format, bi-directional printing at 125 
CPS and sprocket feed paper mech- 
anism. Line length is selectable at 40, 
80 or 132 characters per line. Forms 
may be loaded either from the bottom 
or the rear. Available with parallel or 
asynchromous serial interfacing. 
Weight 22 lbs. 
Cat No. Description Price 

2455 Parallel Interface $834.75 

2456 RS-232 Serial Interface S894.0Q 



€MRKO 22 PRINT€R 



J 



Circle 251 on inquiry card. 



Dept. (38 
19511 Business Center Dr 
Northridge, Calif. 91324 

BYTE August 1980 285 



Circle 252 on inquiry card. 




BUILD YOUR OWN LOW COST 
MICRO-COMPUTER 

POWER SUPPLIES 

FOR S-100 BUS, FLOPPY DISCS, ETC. 




POWER TRANSFORMERS (with mounting brackets) 



ITEM 
NO. 



USED IN 
KIT NO. 



PRI. WINDING 
TAPS 



SECONDARY WINDING OUTPUTS 
2x8 Vac 2x14 Vac 2x24 Vac 



SIZE 
W x D x H 



UNIT 
PRICE 



T1 
T 4 



OV, 110V, 120 V 
0V, 110V, 120V 
V, 110V, 120V 
0V, 110V, 120V 



2x7.5A 

2X12.5A 

2x9A 

2x4A 



2x2.5A 
2x3.5A 
2x2.5A 
(28 V, CT) 



2x2.5A 

48V, CT, @3A 

POWER SUPPLY KITS (open frame with base plate, 3 hrs. assy, time) 

ITEM USED FOR @+8 Vdc @-8Vdc @+i6Vdc @-16Vdc @+28Vdc 



3 3 /4"x3 s /e"x3'/B" 
3%"x4%"x3Ve" 
3%"x4%"x3Vb" 
3%"x3 5 /8"x3V8" 



21.95 
27.95 
29.95 
22.95 



SIZEWxDxH UNIT PRICE 



KIT1 15 CARDS SOURCE 15A 

KIT 2 SYSTEM SOURCE 25A 

KIT 3 DISC SYSTEM 15A 

KIT 4 DISC SOURCE 8A 



2.5A 2.5A 

3A 3A 

2A 2A 

*(SEE OPTION BELOW) 



12"x6"x4%" 
12"x6"x4%" 
14"x6"x4 7 /s" 
10"x6"x4%" 



51.95 
58.95 
66.95 
49.95 



1A 2A 2A 4A 

1A '(SEE OPTION BELOW) 5A 

EACH KIT INCLUDES: TRANSFORMER, CAPACITORS, RESIS., BRIDGE RECTIFIERS, FUSE & HOLDER, TERMINAL BLOCK, BASE 
PLATE, MOUNTING PARTS AND INSTRUCTIONS. 'OPTION OF KIT 4: SUBSTITUTE ± 16V, @4A, FOR + 28V, @5A. 

DISC DRIVE POWER SUPPLY "R3" assy. & tested, open frame, size: 9" <w> x 5" (D) * 5" (H) 64.95 

SPECS: +5V@5A REGULATED, -5V@1A REG., +24V@5A REG., SHORTS PROTECT. OPTION: SUBSTITUTE ±12V@4A 
IDEALFOR2SHUGART801/851ORSIEMANSFDD100-8/200-8DISKDRIVES&ROCKWELLAIM-65. FOR - 5V & + 24V. 

SHIPPING FOR EACH TRANSFORMER: $4.75, FOR EACH POWER SUPPLY: $5.00 IN CALIF. $7.00 IN OTHER STATES. CALIF. RESIDENTS ADD 6% SALES TAX. OEM WELCOME. 



MAIL ORDER: 

P.O. BOX 4296 

TORRANCE, CA 90510 



SUNNY INTERNATIONAL 

(TRANSFORMERS MANUFACTURER) 
Telephone: (213) 633-8327 



STORE: 

7245 E. ALONDRA BLVD. 

PARAMOUNT, CA 90723 

STORE HOURS: 9 AM-6 PM 





BECKIAN I 








ALL PRIME QUALITY - NEW PARTS ONLY 




















SATISFACTION GUARANTEED. 










EDGE CARD CONNECTORS: 


GOLD PLATED: 












Abbreviations: S/E Solder Eye 


. S/T Sold Tail: 


W/W Wire Wrap. 






PART tt DESCRIPTION. Row Sp. 


1-Spc. 16-24pcs. 25pci. Up. 


.156" CONTACT CENTER CONNECTORS. 








'D' TYPE SUBMINIATURE CONNECTORS. 




BRAND: 


TEXAS INST. 






PART * DESCRIPTION. 


Row Sp. 


19pc. 


10-24pca. 25pcs. Up. 








4070 


501100 ImiailCrom. .250 


•3.95eo. )3.55oa. »3.15aa. 


15105 


6112 SIE PETINSC 


.140 


• 1.80 


• 1.65 11.45 








4090 


50/1 DO Imui W1W .250 


4.36aa. 3.95ae. 3.45ea. 


15110 


6112 S/T PETINSC 


.140 


1.85 


1.65 1.56 




2599pc 


BRAND: 


SULLINS: U.L Rag. 






15137 


6/12 S/T PETINSC 


.206 


1.80 


1.54 1.45 


DF 


8P Mela •1.60ea. I1.40ea. 


• I.JOea 


1298B5 


501100 Seldar Ey> .140 


8.80ea. 6.1 DM. 5.45aa. 


15175 


61- SIE Sgle Row 




1.70 


1.50 1.36 


DF 




1.96ea 


129870 


601100 S/T Imui .250 


4.50ea. 4.1 Oaa. 3.70 


15270 


16126 SIE 


.140 


2.15 


1.95 1.76 


DF 


1108631 2 pc. Grey Hood. 1.56ea. 1.35ee. 


1.20ea 


12987S 


501100 WIW Imui .250 


5.25 4.75 4.20 


15275 


10120 S/T 


.140 


2.00 


1.95 1.60 






129885 


50/100 S,T Alltir .140 


4.95 4.45 3.95 


15435 


12/24 S/E PET 


.140 


2.60 


2.35 2.16 


DA 


15P Male 2.35ee. 2.15m. 


2.00aa 


129990 


501100 ST Cromam. .250 


4.75 4.25 3.90 


15446 


12124 S/T PET 


.140 


2.65 


2.40 2.15 


M 


15S Female 3.25ee. 3.10ea. 


2.90ea 










15445 


12124 S/T PET 


.260 


2.75 


2.50 2.20 


DA 


512111 1. pc. Grey Hood 1.40m. 1.20aa. 


I.ISea 


OTHER . 


25" CONTACT CTR CONNECTOR! 






15505 


15130 SIE GRI Key 


.140 


2.56 


2.25 2.00 


DA 


512261 2 pc. Black Hood 2.50ee. 2.25ea. 


2.00ea 


12305 


22/44 SIE No Earl .140 


4.15 3.75 3.35 


15516 


15130 S/T GRI Key 


.140 


2.46 


2.15 2.95 


DA 


1109632 2 pc. Grey Hood 1.66aa. 1.35ea. 


UOsa 


12759 


36/72 S/T .140 


5.40 4.85 4.35 


15515 


15130 WIW GRI Key .206 


2.66 


2.35 2.10 








12790 40190 WW .250 
.100" CONTACT CTR CONNECTORS: 


6.30 5.65 5.00 


15666 
15616 
15615 


18136 SIE 
18136 SIT 

18130 WIW 


.140 
.140 
.200 


3.35 
3.60 

3.60 


3.05 2.76 
2.76 2.46 
3.20 2.80 


DB 
DB 


25S Female 3.66ea. 3.46ee. 
51212-1 1 pc. Grey Hood 1.56ee. 1.36ea. 


3.20ea 
I.IOes 


10048 


13/26 SIE No Eari .146 


3.40 3.05 2.15 


15760 


22144 SIE KIM/VEC .140 


2.98 


2.90 2.75 


UK 


512261 2 pc. Black Hood 1.90ea. 1.65ea. 




10280 


25/50 SIE TRS 06 .146 


4.50 4.05 3.60 


15705 


22144 S/T KIM/VEC .140 


3.98 


3.30 3.00 








10175 


26/40 SIE TRS 86 .140 


5.65 5.35 4.75 


15710 


22144 WIW KIM/VEC .200 


3.49 


3.20 2.85 


DC 


37P Mala 4.20aa. 4.00ea. 


3.70si 


10180 


20146 WIW TRS 86 .266 


3.36 3.66 2.15 


15675 


25150 SIE 


.140 


4.65 


4.20 3.75 


DC 






10190 


26146 S/T TRS 86 .146 


3.20 2.96 2.55 


15680 


25150 S/T 


.140 


4.55 


4.10 3.65 


DC 


1108634 2 pc. Grey Hood 2.25ea. 2.60ee. 


1.75ei 


104B5 


36172 S/E Vector .140 


5.56 4.96 4.40 


15885 


25150 WIW 


.200 


4.85 


4.35 3.96 








10490 


36/72 W/E Vactor .266 


5.80 5.25 4.65 


16115 


36/72 SIE 


.140 


6.56 


5.85 5.26 


DD 


50P Male 5.5 Oea. 5.1 Oaa. 


4.7501 


10500 


38/72 S/T Vector .146 


5.70 4.20 4.60 


16120 


36172 S/T 


.140 


6.55 


5.80 5.25 


DD 


50S Female 9.40ea. 8.60ee. 


B.OOei 


10535 


46/60 SIE PET .146 


5.85 5.35 4.75 


16125 


36172 WIW 


.200 


6.75 


6.10 5.40 


on 


51216-1 1 pc. Grey Hood 2.46ea. 2.20oa. 


2. 001 


10540 


46166 WIW PET .200 


6.66 5.46 4.86 


16145 


36172 S/T 


.200 


6.56 


5.85 5.26 


DD 


110963 5 2 pc. Grey Hood 2.66ee. 2.40ee. 


2.1 Obi 


10550 


40/80 SIT PET .140 


5.80 5.25 4.65 


16235 


43186 S/T Mot 6860 .146 


6.86 


5.95 5.36 








1D585 


43/86 SIE COS/ELF .140 


6.95 6.25 5.55 


16240 


43/86 WIW Mot 6606 .206 


7.86 


7.65 6.25 




11 Hood Sail 




10805 


43186 S/T COS/ELF .140 


6.66 5.95 5.36 


16280 


43186 SIT Mot 8860 .266 


6.56 


5.85 5.26 






10595 


43186 WIW COS/ELF .200 


6.86 6.26 5.95 


16725 


43/86 SIE Mot 6860 .140 


7.20 


6.56 5.75 








10619 


43106 S/T COSIEIF .206 


6.86 6.16 5.46 


K1 


Pol-Keys 




.15 


.12 .10 












I.C. SOCKETS GOLD. 










COOLING FANS. 




TERMS: MINIMUM ORDER: $15.00 ADO $1 


35 Fo 






WIWRAP 3 TURN 








Extra Quiet. 




Handling & Shipping. Orders over $30.00 in the U.S. A 






14 pin 


10.40 aa. 


14 pin 




•6.15 ee. 


1 to 4 




•16.66 ea. 




We Pay the Shipping. CALIF. RESIDENTS: Please Ad. 






16 pin 


6.44 ea. 


16 pin 




6.17 eo. 


5 to 9 




17.60 ee. 




6% Sales Tax. 

NOTE: NO C.O.D. OR CREDIT CARD ORDERS 
ACCEPTED. 




8080A PRIME. 


A/ILL B 






















• 5.00 ea. 




CONNECTORS F 


)R CENTRONICS 700 SERIES, 
ihenol 57 30366 

$8.00 ea. 


PHONE: 213-988-6196 


BECKIAN ENTERPRIS 




EIA 8 CONDUCTOR CABLES 8ft. Long. 


ES 






CLASS #1 Type 


Cablet. 


1 to 4 pes. 




MAIL ORDERS TO: 


P.O. BOX #3089 








1 . to 4 pes. 
5 to 8 pes. 


• 22.60 
19.66 


5 to 9 pes. 




6.60 ea. 








SIMI VALLEY, CA 93063 



286 BYTE August 1980 



Circle 253 on inquiry card. 



NEW PRODUCTS! 
Super Color S-1 00 Video Kit $1 29.95 Elf II Adapter Kit $24.95 

Expandable to 256 x 192 high resolution color Plugs into Elf II providing Super Elf 44 and 50 pin 
graphics. 6847 with all display modes computer plus S-100 bus expansion. (With Super Ex- 
pansion). High and low address displays, state 
and mode LED's optional $18.00. 

Gremlin Color Video Kit $69.95 

32 x 16 alpha/numerics and graphics, up to 8 
colors with 6847 chip; IK RAM at E000. Plugs 
into Super Elf 44 pin bus. No high res. graphics. 



controlled. Memory mapped. 1K RAM expanda- 
ble to 6K. S-100 bus 1802, 8080, 8085, Z80 etc. 
Delivery January '80. 
1802 16K Dynamic RAM Kit $149.00 

Expandable to 32K. Hidden refresh w/clocks up to 4 
MHz w/no wait states Addl. 16K RAM $63 

Quest Super Basic 

Quest, the leader in inexpensive 1802 systems 
announces another first. Quest is the first com- 
pany worldwide Co ship a full size Basic for 1802 
systems. A complete function Super Basic by 
Ron Cenkor including floating point capability 
with scientific notation (number range ±.17E 3 "), 
32 bit integer ± 2 billion; Multi dim arrays; String 
arrays; String manipulation; Cassette I/O, Save 
and load, Basic, Data and machine language pro- 
grams; and over 75 Statements, Functions and 
Operators. 

Easily adaptable on most 1802 systems. Re- 
quires 12K RAM minimum for Basic and user 
programs. Cassette version in stock now. ROM 
versions coming soon with exchange privilege 



allowing some credit for cassette version. New 
improved version with improved speed and accu- 
racy now avail. Source list for I/O now incl. 

Super Basic on Cassette $40.00 

Tom Pittman's 1802 Tiny Basic Source listing 
now available. Find out how Tom Pittman wrote 
Tiny Basic and how to get the most out ol it. 
Never offered before. $19.00. 

S-100 4-Slot Expansion $ 9.95 

Super Monitor VI. I Source Listing $15.00 

Coming Soon: Assembler, Editor, Disassem- 
bler, DA/AD, Super Sound/Music, EPROM 
programmer, Stringy Floppy System. 




RCA Cosmac Super Elf Computer $106.95 



Compare features before you decide to buy any 
other computer. There is no other computer on 
the market today that has all the desirable bene- 
fits of the Super Elf for so little money. The Super 
Elf is a small single board computer that does 
many big things. It is an excellent computer for 
training and for learning programming with its 
machine language and yet it is easily expanded 
with additional memory, Full Basic, ASCII 
Keyboards, video character generation, etc. 
Before you buy another small computer, see if it 
includes the following features: ROM monitor; 
State and Mode displays; Single step; Optional 
address displays; Power Supply; Audio Amplifier 
and Speaker; Fully socketed for all IC's; Real cost 
of in warranty repairs; Full documentation. 
The Super Elf includes a ROM monitor for pro- 
gram loading, editing and execution with SINGLE 
STEP for program debugging which is not in- 
cluded in others at the same price. With SINGLE 
STEP you can see the microprocessor chip opera- 
ting with the unique Quest address and data bus 
displays before, during and after executing in- 
structions. Also, CPU mode and instruction cycle 
are decoded and displayed on 8 LED indicators. 
An RCA 1861 video graphics chip allows you to 
connect to your own TV with an inexpensive video 
modulator to do graphics and games. There is a 
speaker system included for writing your own 
music or using many music programs already 
written. The speaker amplifier may also be used 
to drive relays for control purposes. 



A 24 key HEX keyboard includes 16 HEX keys 
plus load, reset, run, wait, Input, memory pro- 
tect, monitor select and single step. Large, on 
board displays provide output and optional high 
and low address. There is a 44 pin standard 
connector slot for PC cards and a 50 pin connec- 
tor slot for the Quest Super Expansion Board. 
Power supply and sockets for all IC's are in- 
cluded in the price plus a detailed 1 27 pg . instruc- 
tion manual which now includes over 40 pgs. of 
software info, including a series of lessons to 
help get you started and a music program and 
graphics target game. Many schools and 
universities are using the Super Elf as a course 
of study. OEM's use it for training and R&D. 
Remember, other computers only offer Super Elf 
features at additional cost or not at all. Compare 
before you buy. Super Elf Kit $106.95, High 
address option $8.95, Low address option 
$9.95. Custom Cabinet with drilled and labelled 
plexiglass front panel $24.95. Expansion Cabinet 
with room for 4 S-100 boards $41.00. NiCad 
Battery Memory Saver Kit $6.95. All kits and 
options also completely assembled and tested. 
Questdata, a 12 page monthly software pub- 
lication for 1802 computer users is available by 
subscription for $12.00 per year. Issues 1-12 
bound $16.50. 

Tiny Basic Cassette $10.00, on ROM $38.00, 
original Elf kit board $14.95. 1802 software; 
Moews Video Graphics $3.50. Games and Music 
$3.00, Chip 8 Interpreter $5.50. 



Super Expansion Board with Cassette Interface $89.95 



This is truly an astounding value! This board has 
been designed to allow you to decide how you 
want it optioned. The Super Expansion Board 
comes with 4K ol low power RAM fully address- 
able anywhere in 64K with built-in memory pro- 
tect and a cassette Interface. Provisions have 
been made for all other options on the same 
board and it fits neatly into the hardwood cabinet 
alongside the Super Elf. The board includes slots 
for up to 6K of EPROM (2708, 2758, 2716 or Tl 
2716) and is fully socketed. EPROM can be used 
tor the monitorand Tiny Basic or other purposes. 
A IK Super ROM Monitor $19.95 is available as 
an on board option in 2708 EPROM which has 
been preprogrammed with a program loader/ 
editor and error checking multi file cassette 
read/write software, (relocatible cassette file) 
another exclusive from Quest, it includes register 
save and readout, block move capability and 
videographics driver with blinking cursor. Break 
points can be used with the register save feature 
to isolate program bugs quickly, then follow with 
single step. The Super Monitor is written with 



subroutines allowing users to take advantage of 
monitor functions simply by calling them up. 
Improvements and revisions are easily done with 
the monitor. If you have the Super Expansion 
Board and Super Monitor the monitor is up and 
running at the push of a button. 
Other on board options include Parallel Input 
and Output Ports with full handshake. They 
allow easy connection of an ASCI I keyboard to the 
input port. RS 232 and 20 ma Current Loop for 
teletype or other device are on board and if you 
need more memory there are two S-100 slots for 
static RAM or video boards. Also a 1K Super 
Monitor version 2 with video driver for full capa- 
bility display with Tiny Basic and a video interface 
board. Parallel I/O Ports $9.85, RS 232 $4.50, 
TTY 20 ma l/F $1.95, S-100 $4.50. A 50 pin 
connector set with ribbon cable is available at 
$15.25 for easy connection between the Super 
Elf and the Super Expansion Board. 
Power Supply Kit for the complete system (see 
Multi-volt Power Supply below). 



Same day shipment. First line parts only 
Factory tested. Guaranteed money back 
Quality IC's and other components at fac 
tory prices. 

INTEGRATED CIRCUITS 



P.O. Box 4430X, Santa Clara, CA 95054 
Will calls: 2322 Walsh Ave. 
^(408) 988-1640 



7400TTL 

7400N 
7402N 
7404N 
7409N 

~410N 



7414f\ 
7420N 
7422N 
7430N 
7442N 
7445N 
7447N 
74461*4 
7450N 
7474N 
7475N 
7485N 
74S9N 
7490N 
7492N 
7493N 
7495N 
74100N 
7-I107N 
71121N 
711 23N 
71125N 
74145N 
7J150N 
74151N 
741 54N 
741S7N 
74161N 
74162N 
74163N 
74174N 
741 75N 
741 90N 
74192N 
741S3N 
74221N 
74298N 
74365N 
74366N 
74367N 

74LSQO TTL 

74LSDQN 

74LS02N 

74LS04N 

74LSQ5N 

74LS08N 

74LSI0N 

74.S13N 

74.S14N 

74L520N 

74LS22N 

74LS28N 

74LS3QN 

74LS33N 

74LS3BN 

74LS74N 

74LS75N 

74LS90N 

74LS93N 

74LS95N 

74LS107N 

74LS112N 

74LS113N 

74LS132N 

74LSI36N 

74LS151N 

74LS155N 

74LS157N 

74LS162N 

74LS163N 1.65 

74L5174N 2.00 

74LSI90N 1.25 

74LS221N 2.50 

74LS258N 1.60 

74LS367N 1.65 

LINEAR 

CA3045 .90 

CA3046 1 10 

CA3081 180 

CA33B2 1.90 

CA3D89 2.95 

LM301AN/AH 35 

LM305H .67 

LM307N 35 

LM30BN 1.00 

LM309K 1.50 

LM311H/N .90 

LM317M 3.75 

LM316 t 35 

LM320K-5 1 50 



LM323K-5 5.35 

LM320K-12 1.50 

LM320K-15 1.50 

LM320T-5 1.35 

LM320T-B 1.35 

LM320T-I2 1.35 

LM320M5 1.35 

LM324N 1.40 

LM339N 1.00 

LM340K-5 1-35 

LM340K-B 1.35 

LM34DK-12 1.35 

LM34QK-15 1.35 

LM340K-24 1.35 

LM340T-5 1.25 

LM34DT-8 1.25 

LM340T-12 1.25 

LM340M5 1.25 

LM340T-18 1,25 

LM340T-24 1.25 
LM350 



LM377 

LM379 
LM38QN 
LM361 
LM3B2 
LM703H 
LM709K 
LM723H/N 
LM733N 
LM741CH 
LM741N 
LM747H/N 
LM748N 
LM1303N 
LM1304 
LM13D5 
LM1307 
LM13I0 
LM145S 
LM18O0 
LM1B12 
LM1889 
LM2I11 
LM2902 
LM3900N 
LM3905 
LM3909N 
MC145BV 
NE550N 
NE55SV 
NE556A 
NE5B5A 
NE566V 
■ NE567V 
NE570B 
78L05 



75491CN 
75492CN 
75494CN 



3.50 



Ala D CONVERTER 



B700CJ 

8701 CN 

B75DCJ 

LO130 

940DCJV.F 

ICL7103 

ICL7107 



CD4026 

CO 4027 

CD4028 

CD4D29 

CD4D30 

CD4035 

CD4040 

CD4042 

CO4043 

C04044 

CD4046 

CD4049 

C04050 

CD405I 

C04O50 

CD4D66 

CDJ06B 

CD 4069 

CD4070 

CD4071 

C04072 

C04073 

CD4075 

CD4076 

CD407B 

CD 4061 

CD4082 

CD41I6 

C04490 

CD4507 

CD450D 

CD45I0 

CD451I 

CD4515 

C04516 

C04518 

CD4520 

CD4527 

CD452B 

CD4553 

CD4566 

CD4583 

CD4585 

CD401H2 

74C00 

74C04 

74C10 

74C14 

74C20 

74C30 

74C48 

74C74 

74C76 

74C90 

74C93 

74C154 

74C160 

74C175 

74C192 

74C221 

74C905 

74C9Q6 

74C914 

74C922 

74C923 

74C925 

74C926 

74C927 




ELECTRONICS 



1.35 
.45 

1.35 

1.35 
.85 
.85 
.85 

1.67 
.45 
.49 


4116 200ns 


9.50 




6/4116 200ns 60.00 




2513R 


R30 




MM 5262 


40 




MM52B0 


;tiHi 




MM5320 


9.95 


CONNECTORS 


MM5330 
PD411D-3 


5.94 
4.00 


30 pin edge 2 50 


PD4I10-4 


5.00 




P5101L 


6.95 


100 ptn edge WW 5.25 














IC SOCKETS 








Solder Tin Low Prollle 








PIN 1 UP PIN 1UP 


.40 

.GO 


MM57100 


4.50 


B .15 22 30 


GIAY3B500-I 


HWi 


14 .14 24 .35 


MCM66751A 


9.95 














410D 


10 00 


20 .29 40 .57 



KEYBOARDS 

56 key ASCII keyDoard til 

Fully assembled 

53 key ASCII keyboard Kit 

Fully assembled 

Enclosure Plastic 

Mela I Enclosure 



167.50 

77.50 
60,00 
70.00 
14 95 
29.95 



.II «• 

165 CLOCKS 

..10 MM5311 

35 MM5312 3 

35 MM5314 3. 

47 MM5369 2. 

5.50 MM5B41 14, 

1.00 MM5B65 7. 

4.25 CT7001 5, 

102 CT7010 8. 

.94 CT7015 B. 

2.52 MM5375AA/N 3 

" MM5375AG/N ' 



2 MM: 
4 MHz 



1 .02 7205 

1.02 7207 

1.51 7206 

.79 7209 

3.50 DS0026CN 

2.25 DS0056CN 

2 35 MM53104 

1 ]P mi rim i 'it in 



6504 
6522 
6800 
6802 
E820 
6850 



Z80A 
8212 
6214 
6216 
8224 
8228 
8251 
8253 
8255 
8257 
8259 



16.50 
7.50 
15.95 



5MK; 

10 MHr 4.25 

■ 8 MHz 3 90 

20 MHz 3.90 

32 MHz 3.90 

3276BHZ 4.00 

%%l 18432 MHz 4 50 

i'l 3 5795 MHz 1 20 

}'£ 2 0100 MHz 1.95 

£M 2.097152 MHz 4 50 

ISSOR 2.4576 MHz 4.50 

10.95 3.276B MHz 4.50 

9.95 5.0688 MHz 4.50 

9.95 5.165 MHz 4.50 

6.95 5 7143 MHz 4.50 

11.95 6.5536 MHz 4 50 

4 95 14.31818 MHz 4.25 

5,95 IB, 432 MHz 4.50 

5,95 22.1184 MHz 4,50 
\?ll KEYBOARD ENCODERS 

"■" AY5-2376 (12.! 

,»■» AY5-3600 17.1 

'J™ AY5-9100 10 J 

i™ AY5-9200 IS,! 

Ill 74C922 5.E 

'•59 74C923 5J 

2 A «l HD0165-5 6.1 

<•» AY5-9400 I0.E 



CMOS 

CD4000 
CD4001 
CD4Q02 
CD4O06 
CD40O7 
CD40O8 
CD4009 
CD4010 
CD40II 
C04Q12 
CD4013 
CD4014 
CD4015 
CD4016 
CD4Q17 
CO 401 8 
CO4019 
CD4020 
CD4021 
CD4022 
CD4023 
CD4024 
CD4025 



is'nn D Connectors RS232 
575 DB25P 2.95 

10 95 0325S 3.95 

14.95 Cover 1,50 

152 1602CP plas 13.95 EJE9S 1.95 

MS 1802DP plas. 17.95 DAW 2.10 

,S 1B61P 11.50 DA15S 3.10 

CDP1002CD 19.95 HIcM 3» Dlflll LED mil- 
' nn llmiler 69.95 

Stopwatch Kit 26.95 
Auto Clock Kit 17.95 
Digital Clock Kll 14.95 

8K/16K Eprom Kit 

35 {less PROMS' 569 

s Moinerboird S39 

75 Extender Board SB 



RESISTORS Vi watt 5% 
10 pet type .03 
25 per type .025 
100 pet type .015 
1000 pei type .012 
350 piece pack 
5 per type 6.75 

'/1 watt 5% per type 05 



LEDS 

HedTOIB ,15 

Gioen. Yellow T018 .20 

Jumbo Red .20 

Green, Orange, Yellow Jumbo .25 
Cllplite LED Mounllng Clips 8/51.25 
(speaty led, amber, green, yellow, dear) 

CONTINENTAL SPECIALTIES in (lock 
Complete line ot breadboard lest equip 
MAX-100 B digit Fraq. Ctr. S12B.95 
OK WIRE WRAP TOOLS In stock 
Portable Mullfmeler 118.00 

Complete line ol AP Products in slock. 

SPECIAL PRODUCTS 
MM5B65 Stopwatch Timer 

wild 10 pg. spec. 9.00 

PC board 7.50 

Switches Mom. Pushbutton 27 

3 pos slide 25 

Encoder HDD! 65-5 6 95 

Paratronlci 100A Logic 

Analyzer Kll $224.00 

Mpdel 10 Trigger 

Expander Kit S229.00 

Model 150 Bus 

Grabber Kit S369 00 

Sinclair 3Vi Olgll 

Multimeter $59.95 

Clock Calender Kit $23.95 

2.5 MHz Frequency 

Counter XII S37.50 

3D MHz Frequency 

Counter Kll $47.75 



TRANSFORMERS 

6V 300 ma 3.25 

12 Volt 300 ma transformer 1.25 

12.6V CT 600 ma 3.75 

12V 250 ma wall plug 2 95 

12V CT 250 ma wall plug 3.50 

24V CT 400 ma 3.95 

10V 1.2 amp wall plug 4.85 
12V 6 amp 12.95 

12V 500 ma wall plug 4.75 

12V lamp wall plug 6.50 

12V 3 amp 8 50 

10/15 VAC 8'16VA wall plug 9 75 

DISPLAY LEDS 

MAM CA 270 2 90 

MAN3 CC 125 39 

MAN72/74 CA^CA .300 1.00 
DL704 CC .300 1 25 

DL707/OL707R CA 300 U~ 



8095 


.65 
.65 


CDPIB020 
CDPI861 


25.00 
12.95 






UART/FIFO 








AY510I3 


5.50 




1.25 


AYS- 101 4 


7.50 


6T1D 


4.50 


3341 


6.95 


8T13 


3.00 






8T20 








BT23 


3.10 




case6. 










8T25 






24.50 






2716 Inlel 


34.95 




















2758 


22.50 










MOS/MEMORY HI' 




2101-1 








2102-1 




















N82S123 


6.50 








3.75 








6.50 






NB2S131 


8.50 








8.75 
















2114L 450ns 6.40 


8223 


2.90 



DL727/72B 

01747(750 

DL750 

FND359 

FN0500/507 

FNO50 3/510 

FNDB00/BO7 

3 digit Bubble 

4 digit Bubble 
DG8 Fluorescent 
DG 10 Fluorescent 

5 digit 14 pm display 
10 digit display 
7520 Clalre< photocells 
TIL311 Hex 
MAN 3640 



1.90 
1.95 

CC 600 1 95 

CC 357 .70 

COCA 500 1 35 

COCA .500 .90 

CC'CA .BOO 220 



MAN46I0 
MAN4640 
MAN4710 
HAN4740 

MAN6640 
MAN6710 
MAN6740 



.39 

9.50 
CC .30 110 
CA .40 1.20 
CC .40 120 
CA .40 .95 
CC .40 1 20 
CC 56 2.95 
CA 60 



CC .1 



1.35 



MA1002A 

MA1002E 

MA1012A 

102P3 (rantlormer 

MA1012A Transformer 



Rockwell AIM 65 Computer 

6502 based single board with full ASCII keyboard 
and 20 column thermal printer. 20 char, alphanu- 
meric display, ROM monitor, fully expandable. 
$375.00. 4K version S450.00. 4K Assembler 
$85.00. 8K Basic Interpreter $100.00. 

Special small power supply for AIM65 assem. in 
frame $49.00. Complete AIM65 in thin briefcase 
with power supply $485.00. Molded plastic 
enclosure to fit AIM65 plus power supply $47.50. 
Special Package Price: 4K AIM, 8K Basic, power 
supply, cabinet $599.00 

AIM65/KIM/VIM/Super Elf 44 pin expansion 
board; 3 female and 1 male bus. Board plus 3 
connectors $22.95. 

AIM65/KIM/VIM I/O Expansion Kit; 4 parallel and 
2 serial ports plus 2 internal timers $39.00. PROM 
programmer for 2716 $150.00. 32K RAM Board 
assem. $419.00. I6K RAM assem $360.00 

Multi-volt Computer Power Supply 

8v 5 amp, ±18v .5 amp, 5v 1.5 amp, -5v 
.5 amp, 12v .5 amp, -12 option. ±5v, ±12v 
are regulated. Kit $29.95. Kit with punched frame 
S37.45, $4.00 shipping. Kit of hardware $14.00. 
Woodgrain case $10.00, $1 .50 shipping. 

PROM Eraser 

Will erase 25 PROMs in 15 minutes. Ultra- 
violet, assembled $37.50 
Safety switch/Timer version $69.50 

60 Hz Crystal Time Base Kit $4.40 

Converts digital clocks from AC line frequency 
to crystal time base. Outstanding accuracy. 

NiCad Battery Fixer/Charger Kit 

Opens shorted cells that won't hold a charge 
and then charges them up. all in one kit w/full 
parts and instructions. $7.25 



LRC 7000-1 Printer S389.00 

40/64 column dot matrix impact, std. paper. 

Interface all personal computers. 

S-100 Computer Boards 

8K Static RAM Kit S129.00 

8K Static Godbout Econo IIA Kit 145.00 
16K Static Godbout Econo XIV Kit $285.00 
24K Static Godbout Econo VIIA-24 Kit 435.00 
32K Static Godbout Econo X-32 Kit $575.00 
16K Dynamic RAM Kit 199.00 

32K Dynamic RAM Kit 310.00 

64K Dynamic RAM Kit 470.00 

Video Interface Kit $129.00 

80 IC Update Master Manual $55.00 

Complete IC data selector, 2700 pg. master refer- 
ence guide. Over 51,000 cross references. Free 
update service through 1980. Domestic postage 
$3.50. 79IC Master closeout $29.95. 

Z80 Microcomputer 

16 bit I/O, 2 MHz clock. 2K RAM. ROM Bread- 
board space. Excellent for control. Base Board 
$28.50. Full Kit $99.00. Monitor $20.00. Power 
Supply Kit S35.00. 

Video Modulator Kit $8.95 

Convert TV set into a high quality monitor w/o 
affecting usage. Comp. kit w/full instruc. 

Modem Kit $60.00 

State of the art, orig., answer. No tuning neces- 
sary. 103 compatible 300 baud. Inexpensive 
acoustic coupler plans included. 

BSR Controller $39.95 

Connect your computer to the BSR Home Control 
System. Computer controlled ultrasonic trans- 
mitter for your BSR. Software for 1802 user 



TERMS: $5.00 min. orderU.S. Funds. Calit residents add 6% tax. 
BankAmericard and Master Charge accepted. 
Shipping charges will be added on charge cards. 



FREE: Send for your copy of our NEW 1980 
QUEST CATALOG. Include 28c stamp. 



Circle 254 on inquiry card. 



BYTE August 1980 287 




SPRINT 68 
MICROCOMPUTER 

CONTROL COMPUTER 
DEVELOPMENT SYSTEM 

6800 MPU, serial I/O, 48K RAM, dual 8" 
drives, WIZRD multitasking DOS, 
Editor, Assembler, 12K BASIC all for 
$3995. 

SOFTWARE OPTIONS 

C compiler, PL./W compiler, PASCAL 

HARDWARE OPTIONS 

EROM Programmer, analog I/O, parallel 
I/O, 488 GPIB 



WliVTHK 



Corp 



1801 South Street 
Lafayette, IN 47904 
Phone: (317) 742-8428 



APPLE II PLUS WITH 48K RAM 


$1190. 


TEXAS INSTRUMENT 99/4 COMPUTER 


S 989. 


Tl 810 PRINTER 


S1590 


Tl 820 PRINTER 


S1890. 


CENTRONIC PRINTERS: 




730-1 PARALLEL PRINTER 


S 699, 


737-1 PARALLEL INTERFACE 


$ 879. 


SPINWRITERS FROM NEC 




5510 R/O SERIAL INTERFACE 


S2499, 


5520 KSR SERIALWITH KEYBOARD 


$2790. 


5530 PARALLEL INTERFACE 


$2499 


C0MPRINT912APPLE. TRS-80, PET 


$ 559. 


912SERIAL 


$ 599. 


PAPER TIGER 440 


$ 929. 


440/G 


$ 990 


BASE-2800ST. PRINTER 


$ 559. 


COMMODORE BUSINESS MACHINES 




PET 2001 8K COMPUTER 


$ 695 


PET2001-32K 


$1090. 


PET 8032 80 CHAR. SCREEN 


$1595. 


PET 2022 TRAC. FEED PRINTER 


$ 749. 


PET 2023 FRIC. FEED PRINTER 


$ 679. 


PET 2040 DUAL FLOPPY DISK DRIVE 


S1090. 


PET 8050 1 MEG STORAGE 


$1499. 


ATARI 800 


$ 889. 


INTERTECSUPERBRAINI32K) 


$2595. 


NORTH STAR COMPUTERS 




. HRZ-2-32K-D-ASM 


$2275. 


HRZ-2-32K-Q-ASM 


S2675 


DISPLAY TERMINALS: 




INTERTUBEII 


$ 775. 


HAZELTINE1410 


$ 775. 


1420 


$ 899. 


1500 


$ 999. 


IMMEDIATE DELIVERY FROM STOCK 




MULTI-BUSINESS COMPUTER SYSTEMS 


28 MARLBOROUGH STREET 




4Wa>» PORTLAND CONN 06-180 
^^f- 1203) 342-2747 


i;n 




EVERY MONTH 



BUY, SELL OR TRADE ALL TYPES OF 
COMPUTER EQUIPMENT AND SOFT- 
WARE (pre-owned and new) among 
20,000 readers nationwide in BIG 
(11x14") pages. Classified ads are 
only 10' per word and are indexed for 
easy and fast location. Subscription: 
$10 a year/12 issues. Bank cards ac- 
cepted. Money back guarantee. 

CQiTIPUTeR SHDPPIBR 

P.O. Box F-14 

Titusville, FL 32780 

(305) 269-321 1 



Circle 255 on inquiry card. 



Circle 256 on inquiry card. 



Circle 257 on inquiry card. 



dbis 



YOUR HEADQUARTERS FOR 



SALES * SERVICE • SUPPORT 

THE BEST NEW YORK AREA PRICES 
ON ALL OHIO SCIENTIFIC COMPUTERS 
- LOCAL USERS GROUP - 
BUSINESS AND PERSONAL SYSTEMS 

PROFESSIONAL BUSINESS SOFTWARE: 
Accounts Receivable Accounts Payable 
Wholesale Industry Distribution 
Grants Accounting System 
Payrol I 

ALSO AVAILABLE: 
"Eaton LRC 7000+ Plain Paper Printer. .. $356. 
*0kfdata MIcroline 80 Printer- 
upper/lower case, graphics, any paper, 

software selectable print size 827. 

"Hazeltlne 1420 Terminal 948. 

MASTERCHARGE 6 VISA WELCOME 
Designers & Builders of Information Systems, Inc. 
One Mayfair Road - Eastchester, New York 10707 

(914)779- 5292 (212) 933-4170 



DISK DRIVE/CRT 
SALE 




Shugart 
SA80IR 

for 

RS MOD. II 

Only 

s 485 



Hazeltine 1 000 (unused) '499 

Shugart SA400 «279 

Pertec FD200 *279 FD250 . '359 

MPIB51 »279B52 '349 

SA801Rw/PS/Cab '750 

Dual Drives w/PS/Cab '1640 

Limited Quantities 



MTI 



3304 UJ. MocRrthur Blvd. 
Santo Rna, Cfl 92704 

(714) 979-9923 



CROMEMCO 
SYSTEMS 

DISCOUNTED 

System 2 with 64k RAM— $3 1 95 
System 3 with 64k RAM— $5735 

Discounts up to 20% 

on most Cromemco hardware. 

We carry the full Cromemco line. 

TORREY PINES BUSINESS SYSTEMS 

14260 Garden Rd„ Suite IB 

Poway, California 9ZQ64 

(714) 486-3460 

Add 3% for shipping and handling 
California residents add 6% sales tax 



Circle 258 on inquiry card. 



Circle 259 on inquiry card. 



Circle 260 on Inquiry card. 



80X24 VIDEOTERM ™ 

7X9 MATRIX DISPLAY FOR 

LOWER CASE W/ DESCENDERS Ml l L t I 

m 




columns by 24 lines with easy to read 7x9 dot matrix, 
upper and lower case with descenders using shift lock 
feature • 1 K firmware incorporates PASCA L and BASIC 
protocalls so user is not required to enter machine 
language programs or change PASCALS. Misc. info, or 
Gotoxy files • Compatible with all APPLE II peripherals 
so user won't need new software patches for future 
software products • Crystal controlled dot clock for 
excellent character stability • VIDEOTERM is the same 
size as the Apple language card and power consump- 
tion is held to a minimum through the use of CMOS and 
lower power devices • Character set can be user de- 
finable up to a maximum of 128 symbols of 8x16 dot 
matrix font • Display control character mode and four 
standard display formats controlled by escape sequen- 
ces • Built In light pen capability • Inverse display 
mode • 50/60 HZ operation • Sockets on all IC's. 
PRiCE-Withom graphic EPROM $345 
OPTIONS: Graphics EPROM lino <Jwg.S25 

VIDEO SWITCH PLATE, Inserts 

In case slot to choose between 

APPLEII- and VIDEOTERM $12 mm ™"' 

MANUAL: 115 VK MM 

VIDEX 3060 N.W. Thistle PI. Corvallls. OR 97330 Phone (503) 758-0521 




Circle 261 on inquiry card. 



We are interested in buy- 
ing new or used Zilog com- 
puters & accessories and 
Varian Minicomputers or 
parts. 

Write or telephone: 

Keith Jenkins 
& Associates Inc 

Suite 354, Graybar Building 
420 Lexington Ave 
New York, NY 10170 
(212) 599-0447 



Circle 262 on inquiry card. 



MICROCOMPUTERS and 
PHYSIOLOGICAL SIMULATION 

James E. Randall, Indiana University 
School of Medicine, Bloomington 

Foreword by Arthur C. Guyton, University 
of Mississippi School of Medicine, Jackson 

This book provides microcomputer hardware and 
programs suited For teaching simulations such as 
nerve action potential, cardiac action potential, 
cardiovascular system mechanics, and the glucose 
tolerance test. 

"Sorely needed lor those ot us who are just begin- 
ning to adapt microprocessors to teaching appli- 
cations in Physiology. Dr. Randall is eminently 
qualified to do this special job. He has interacted 
for several years with his potential readers 
through his activities in the American Physiologi- 
cal Society." 

Beverly Bishop 
SUiVV at Bu/foJo, School oj Medicine 
Feb. 1980. 250 pp.. illus. Paper G612H $14.50 
Price is subject to change without notice. 



Addison-Wesley 

Advanced Book Program 

Reading, Mass. 01867, U.S.A. 



II 



Circle 263 on inquiry card. 



Precision 
Engineered Drives 

^^^ More Capacitance: Insures stable Scratch resistant steel cover: Primed and baked 

operation over greater line / enamel finish. Virtually eliminates video interference. Color 

Power supply guaranteed voltaqe variations (105-125 Vac ) / compatible with Radio Shack or Zenith Z89. 

for one year. , I 

Increased ventilation for 

additional cooling: Top, 

side and bottom vents mean lower 

operating temperatures 

for longer life. 




Switch designed with high 
current ratings (10 AMP). 



Transformer designed as integral 
part of system for best line 
regulation. Not separately encased to 
avoid heat build-up providing longer life. 




Simpler, more 
reliable circuitry. 



Designed to UL specifications. Easy access to terminating 

Wide operating temperature range (0°C to 50°C) resistor for easy field 

Tested to 1500 volte-inpjiit to>output isolation for enhanced conversion from drive 

power surge protection to drive 1 , 2, or 3. 



Extender: 

Easy plug-in access 



3-wire groundedjinecord 
for added operator safety. 



With the number of disk drives on the market increasing, 
more and more people are beginning to ask what's under- 
neath that cover. 

The CCI™ series of disk drives have been designed for long 
life and ease of operation. The features shown above are what 
set our CCI drives apart from the rest. With a CCI drive you get 
an integrated professional design! 

If you're still not convinced that you get the most for your 
money with a CCI drive, just ask for our complete specifica- 
tions sheet. Then, compare our disk drives to anyone else's. 

5i/4" DRIVES 

CCI- 100 40 Track (102K Bytes) forTRS-80* Model I $399.00 

CCI-189 40 Track (102K Bytes) for Zenith Z89 $499.00 

CCI-200 77 Track (197K Bytes) forTRS-80* Model I $675.00 

8" DRIVES 

CCI-800 77 Track (1/2 Meg Bytes) forTRS-80* Model II $895.00 

All CCI drives are also available for 220 Vac (50Hz) operation. 

ComputerCity 

175 Main Street, Dept. B-8 , Charlestown, MA 02129 
Hours: 10AM-6PM (EST) Mon.-Fri. (Sat. till 5). 



Operating Systems 

NEWDOS Plus for 51/4", 40 and 77 Track Drives— with over 200 
modifications and corrections to TRSDOS $ 1 1 0.00 

CP/M for Model I, Zenith $ 1 50.00 

CP/M for Model II, Altos $1 99.00 

Software by S&M Systems 

INSEQ-80" -Indexed Sequential Access Method ( ISAM ) 

fortheTRS-80Modell. 
Four machine language programs that can be called from your 
BASIC program via USR functions to access records either sequen- 
tially or randomly. The INSEQ-80 programs maintain all indexes and 
chains for you. Includes reorganization utility to consolidate files. 

$49.95 
Professional Business Software using INSEQ-80 for 
the TRS-80* Model I and Zenith Z89. 
Accounts Payable, Accounts Receivable, 

General Ledger, Payroll per package $99.00 

Inventory per package $125.00 

TO ORDER CALL 

TOLL FREE 1-800-343-6522 

TWX: 710-348-1796 

TM Massachusetts residents call 617/242-3350 

For detailed technical information, call 617/242-3350. 
Freight Collect, F.O.B. Charlestown. 

"TRS-80 is a trademark of the Tandy Corporation 



Products also available from: Radio Shack, NEC, Centronics, Paper Tiger, Tl, Altos, MPI, Zenith, ATARI, Mattel 

PET, OKIDATA, Apple, Eaton/LRC. 

FRANCHISE AND DEALER (NATIONAL/INTERNATIONAL) INQUIRIES INVITED 

Retail Stores: MA: Burlington, Charlestown, Framingham, Hanover NH: Manchester RI: Providence 




Circle 264 on inquiry card. 







fill 


MPATIBLE 

] AS RAM 

1 OPTION. 
1PACIT0R. 

HICKNESS 

ENT. 

TH A ONE 


H&&ffi£T'$BB&QL 1 


■■■■■. in*i* 

8K BYTE STATIC RAM MODULE FDR THE 6800; CO 

WITH THE MOTOROLA EXOBciSB - BUS AND 0-2 KIT 

TWO SEPARATE 4k ADDRESSES; EACH MAY BE USE 

OR TREATED AS ROM. 

SWITCHES SET ADDRESSES AND CONTROL RAMIRO 

ALL IC's ARE SOCKETED; EACH IC HAS A BYPASS C 

ACCESS TIME: 450 NSEC. 

DIMENSIONS; HEIGHT 8.425IN. WIDTH 9.750 IN. T 

.062 IN. 

SIGNALS: H7W, VMA OR VUA IJUMPERI. (2 

STATIC RAM: LOW POWER 2102AN 4L OR EOUIVAL 

THE ALI688K COMES ASSEMBLED AND TESTED W 

YEAR WARRANTY. 

PRICE S250 

APPLIED LOGIC, INC 

P.O. BOX 328 

JAMAICA. NEW YORK 11415 

1212I 459 4064 

'EXOHciser is a trademark of Motorola, Inc. 



The World Has Seen 
Tiny Basic, Tiny Pascal, and Tiny C. 

Until Now, 
Microcomputer LISPs Have Been 
"Tiny LISP." 
TLC-LISP is tiny in only one way: its introductory 
price of S1 5D for aft the features described in the 
"What's New" column of the May BYTE, page 292. 
This offer will only last 'til Sept. 2, 1 9BO; after that 
date, we require £20 for the manual and $250 for 
the complete system. (Cal. residents, always add 
6% sales tax; and foreign orders, please add S3 
for shipping.) 

In All Other Ways, TLC-LISP Is 




It is a BIG subset of MIT's LISP Machine LISP, the 
world's best LISP. It is BIG in performance, averag- 
ing 1 /3 the speed of a KA-1 0. It is BIG in docu- 
mentation, supplying a manual written by John 
Allen, founder of TLC. author of "Anatomy of LISP" 
and editor of BYTE's special LISP issue It is BIG in 
quality, being designed and implemented by a team 
with thirty years combined LISP experience. So, 
get on the TLC-LISP bandwagon early; discover the 
power and flexibility of LISP using the BIG LISP with 
the tiny price. 

(T.(L.O), The LISP Company 

Box 487 Redwood Estates, CA 95D44 




The best choice 
in mainframes ! 

• S100 CARD FRAME • AXIAL BLOWER 

• 22 MHi 12" CRT MONITOR • ASSEMBLED & TESTED 

• 18 AMP POWER SUPPLY • HEADY FOR YOUR CARDS 

• UPPER & LOWERCASE • S895.00 OEM QUANT. ONE 
ASCII KEY BOARDS 



>D 



OOU IN FIN IT 



CefcltmJng Oirr I. I'll Iiw. 
813 E. STRAWBRIDGE. MELBOURNE. FL 32901 - (3051 724-1588 



Circle 265 on inquiry card. 



Circle 266 on inquiry card. 



Circle 267 on inquiry card. 



STATIC RAM CHIPS 

CAPTODV ddimc Fran the same shipmen! we usa in our 
rHOIUni rnllVlt professional quality boards. 

2114L450ns.$5.90 200ns. $6.90 
4044 450ns. $5.90 250ns. $6.90 

Add $5.00 Handling on Orders Under $200.00 

32K STATIC RAM BOARD 

FOR THE SS50 ANP SS50C BUS (SWTP etc.) 

• SS50C Extended Addressing (can be disabled). 

• 4 separate 8K blocks. 

• Low power 2114L RAMS 

• Socketed for 32K 

• Write Protect 

• Gold Bus Connectors 

16K $328.12 

24K $438.14 

32K $548.15 

Phone, write, or see your dealer (or details and prices on our 
broad range of Boards and Syslems for the SS507SS50C bus 
including our UNIQUE 80x24 VIDEO BOARD, and our AC 
Power Control Products (or all computers. 

GimiX (51 

1337 W. 37th Place • Chicago, IL 60609 
(312)927-5510 • TWX 910-221-4055 

The Company that delivers. 

Quality Electronic products since 1975. 

GIMIF and GHOSP are Registered Trademarks ol GIMIX INC. 



Circle 268 on inquiry card. 



3fc 3jc jjc j^c jjc >(c yf. 3ft j^c j^. jjt. ^. t. 



t ;:*THE.. 
GREEN 
SCREEN 



* 

-x- 
* 
* 
* 
* 
* 



*£vo. 



• IMPROVE IMAGE CONTRAST 

• REDUCE EYE FATIGUE 

• ENHANCE SCREEN LEGIBILITY 

• PROVIDE A MORE PLEASING 
DISPLAY 

• GIVE A DISTINCTIVE PROFESSIONAL 
LOOK TO YOUR SYSTEM 

ThB GREEN SCREEN is custom molded to 
fit nicely over the picture tube, 
ft ingeniously mounts in seconds without 
sny tools. » * .*„ 

CALL: (212)296-5916 BBB OHB 
or SBnd $12.50 I S2 SGH ■*■■ tSMB 

ALPHA product co. 

85-71, 79th St., Woodtiavon, N.Y. 11421 
3)C3)cjf:3(t>^S^3tr;3^5(c5(r;5)C3^ 



6502 

FORTH 



... is a structured, high-level macro language well 
suited to microcomputers. 6502 FORTH is avail- 
able now for KIM, SYM. and AIM systems with 
at least 12 K of RAM starring at either $0200 or 
$2000. Includes a built-in 6502 assembler, text 
editor, and virtual memory file software linked 
to the system cassette interface. (An app. note is 
provided which shows how 6502 FORTH can 
easily be interfaced to a low-level disk driver) The 
package, which includes a commented source 
listing of the complete system, object code on 
cassette, and a user manual, sells for $90.00 (in- 
clude $4.00 S&H). Payment must be by U.S. 
check or money order, (Specify system type and 
starting location) The user manual is available 
separately for $15.00 (include $1.50 S&H} 

ERIC C REHNKE 

1067 Jadestone Lane 
Corona, CA 91720 



Circle 269 on inquiry card. 



SAVE 

15-50% 
OF YOUR DISK SPACE 

HUFF n PUFF 

• Bit compress your files with 
savings up to 50% 

• Cut your TP connect time by up 
to 50% 

• Z-80 code compatible with 
CP/M and CROMEMCO CDOS 

• Free 30 day money back 
guarantee 

HUFF n PUFF is available on 8" 
diskette, single or double density 
for $75. 

(California residents add 6% sales 
tax) 

J and S SOFTWARE 

2406 TOItltl JON PLACE 
CAM, SHAD CA. 92008 



H9 OWNCftS! 

Upgrade your video terminal with one 
of these long overdue kits: 

GflflFIX — Graphical display capa- 
bilities assembled and tested $69.95. 
Kit $59.95. 

CURSOR CONTROL - A total of 
8 functions assembled and tested 
$34.95. Kit $29.95. 

FLICK€R FR€€ — 4800 baud 
operation assembled and tested 
$79.95. Kit $69.95. 

Fill have a full 6 month warranty. 

NORTHW€ST COMPUT€R 
SCRVICC-S, INC. 

8503 N.€. 30th Avenue 
Vancouver, UJR 98665 



Circle 270 on inquiry card. 



SUPER SALE 

16K Apple n coo*; on 

or Apple II Plus $77 J.UU 
Apple Disk II 

w/controller $529.95 

Apple Soft or 

Integer Cards $159.95 

Pascal Language Card $459.95 
10 Megabyte Disk 

for Apple $4695.00 

DC Hayes Modems $339.95 
Graphics Tablet $695.00 

UCfiTRTI COmPUTER STDfiE 

P O BOX IOOO DESTIN FL 32541 

ACROSS FROM RAMADA INN 

904837-2022 

Credit Cards Accepted 



Circle 271 on inquiry card. 



Circle 272 on inquiry card. 



Circle 273 on inquiry card. 




mm 



MICRO 

BUSINESS WORLD 

Immediate response to your orders (verbal or written), toll-free (800) 421-0347 







jCippkZ /[ I... Apple II plus 
and the NEW Apple III 

The complete, ready to run computers . . . Connect to your 
color TV and start writing programs today. APPLE is faster, 
smaller, more powerful than it's predecessors. APPLE will 
change the way you think about computers. Call for our Price. 

INVENTORY CONTROL SYSTEM FOR Apple II 

The first truly professional system that can tackle up to 8,100 
items • Transaction register/audit trail • Inventory Status re- 
port • Re-order report • Keeps track of purchase orders auto- 
matically • Will handle multiple departments or divisions 
Fast data retrival. 

Minimum hardware requirements: APPLE I 1 Plus with 48K, 
one disk drive and 80 column printer. 
Introductory Price: $99.00 Including comprehensive manual. 



ZENITH 

DATA 

SYSTEMS 

Smart Video 

Terminal 



Z-89 

Computer 

System: 

includes: Z19 Display, a built in 5V4" 
Floppy Disk. 2 serial ports, and 16K of 
memory. 2295.00 48K Memory 2595.00 
Also 48K Z-19 hasaZ80 Micro -processor, 
numeric keypad and 8 function key. 895.00 




ATARI oUU Computer System 
Packed with: Computer Console, Basic 
Language Card, Education System 
Master Cartridge, Cassette Recorder, TV 
Modulator, 8K Memory (expandable to 
48K), Power Supply & all Books and 
Manuals $799.95 

ilTADI /Ifin Personal Computer 
Ml HHI 4UU System for less 
Packed with: Computer Console, Basic 
Language Cartridge, Power Supply, TV 
Modulator, and all Books and 
Manuals $499.95 

ATARI Program Recorder 69.99 

ATARI Software, Homa, Caaaettea 25% off list price 
ATARI Expanaion Memory 8K Module 99.99 

16K Module 169.99 




ft commodore 




the Great American Solution 



CBM 8050 
DUAL DRIVE 
FLOPPY DISK 




CBM 8000 SERIES BUSINESS COMPUTER 



CBM 2001 SERIES BUSINESS COMPUTER 



DYSAN DISKETTES 

THE CADILLAC OF THE FLOPPY DISKS AT LOW LOW PRICES 

8" (BOX OF 10) • 3740/1 sgl side/ sgl density 4.50 ea 

• 3740/1D sgl side/dbl density 6.95 ea 

5" (BOX OF 5 )• 104/1 soft sector . 107/1 10 sectors 

• 105/1 16 sectors 4.50 ea 




EPSON MX-80 

DOT MATRIX PRINTER 

The new Model MX 80 is a high-speed 
bidirectional, impact printer capable of 
printing 9x9 dot matrix characters. Prints 
enlarged, condensed, condensed/enlarged, 
normal characters with 40,132, 66, 80 col- 
umns per line logical seeking function. 



$645. 




EPSON TX-80 . . . 
DOT MATRIX PRINTER 

with graphics $795. 

16K RAM set of 8 411 6's 
250 ns or better $59.00 



Prices subject to change without notice. 

VISA and MASTER CHARGE WELCOME. Allow 2 weeks for cashiers 
check to clear, 4 weeks for personal checks. Add 2% for shipping and 
handling. Calif, residents add 6% sales tax. (Sorry, no C.O.D.) 

U.S. and International dealer inquiries invited. 

Copyright 1980 • MICRO Business WORLD Circle 274 on inquiry card. 



nrn micro 

|ffj BUSINESS WORLD 






15818 Hawthorne Boulevard 

Lawndale. California 90260(213) 371-1660, 



Teach 

Yourself by 
Computer Software" 



Educalional Software on ALL suDiecls 

lor home and school 
|!oi Apnle" and TRS-80") 



Write lor Iree brochure to; 

Teach Yoursell by Computer Software 

40 Stuyvasan! Manoi 

Geneseo. New York 14454 

716-243-3005 



BET. Paid€ 

for using your 
Computer* 2 



FUN-' Eas-J E53 

RUSH COUPON FOR ^ 
FREE FACTS 

Gfl tP " SPARE TIME 



• W® ; 

Send today to — DAR-B8 
31 10 Fulton Ave, Sacramento CA 95821 




SPECIAL PRICES 



HARDWARE, SOFTWARE, 
PERIPHERALS 

FOR 



tcippkz computers 



Vector Graphics 

Most items in stock for 
immediate delivery. VISA/MC. 

For Our Catalog, Contact 
Computer Distributors 

PO BOX 9194 

AUSTIN, TX 78766 

(512) 345-9729 



Circle 275 on inquiry card. 



Circle 276 on inquiry card. 



Circle 277 on inquiry card. 



COMPUTER FORMS 



DISTRIBUTOR OF COMPUTER PAPER 
PRODUCTS 



All paper products are white, blank, tractor feed, 
IPinfeedl FANFOLD CONTINUOUS stock. 

6"x 4" POSTCARD STOCK |7" width with 54" 
margins). Use as is or trim for 3Vi" x 5Vi" card. 
Pkg 1000 cards. ..517. 95 Pkg 2000. ..$29. 95 
Box 4000. ..$49. 95 

STANDARD 9V4'x 11" COMPUTER PAPER 

(8Vi" x 11" sheetl 
Pkg 500 sheets.. .$5. 95 
Box 3500 sheets. ..$27. 95 
Box shipping weight. ..31 lbs 

TRY OUR MINI-PAPER! 6" x 8)4" sheet size 

(7" width includes Vi" tractor margins! 

Box 3200 sheets. ..$23. 95 Sh. Wt. only 1 7 lbs 



CASH ORDER: Include $2 for shipping, excess will 
be billed with your order. 

CREDIT CARD ORDER: Shipping will be added to 
your order. Include ALL credit card information. 



Send for FREE Catalog of 
Paper Products. Postcard 
stock, address labels, many 
sizes & types of paper. 



CHECK or 
Money Order 



COMPUTER FORMS (6161 429-7922 
5588 Caribou, Stevensville, Ml 49127 



= Diskettes = 

8 inch-so ft/hard sector: 
Sngl side-sngl dens $2.95 
Sngl side-dble dens S3. 55 
Sngl side ■ never shl $4.55 
Ohle side-sngl dens $4.55 
Ohle side-dble dens $4.90 
5 inch-so 1 1 1 hand sector: 
Sngl side ■ 40 Trk $2.75 
Ohle side ■ 40 Trk $4.05 
Sngl side- 7 7 Trk $4.35 

Visa/ Mst.Chg/COD - call 

[20614884552 

HARREX CORPORATION 
Media Sales Division 
P.O. BOX 249 
Kenmoro, Wash. 98028 



Circle 278 on inquiry card. 



Circle 279 on inquiry card. 



Now on Disk 

Learn FORTH 

FORTH is a structured high level language thai dramatically 
CtltS program development time. You ear) expand the 
FORTH language by defining new operations and data types. 
FORTH programs are compiled 10 reduce memory space and 
speed execution. 

linyFORTH is a complete version of the powerful FORTH 

language tailored to the TRS-80. The disk linyFORTH sys- 
tem is a stand-alone operating system with FORTH, a text 
editor, an assembler, and graphics 

Leurn FORTH on your own computer. The linyFORTH 

user's manual contains hundreds of examples to teach you 
FORTH in a hands-on style. 

linyFORTH for 16k level II TRS-80: 

Disk version and full documentation . ,$49.95 

Cassette version and full documentation $29.95 

Documentation only (disk version) $14.95 

All orders are fully guaranteed Add SI. 50 for postage and 
handling. Order with check, money order. Visa, or Master- 
charge. 

Write for a FREE booklet describing FORTH. 

The Software Farm 

Box 2304 Dept. A30 Reston, VA 22090 

Circle 280 on inquiry card. 



STRUCTURAL ANALYSIS 
SOFTWARE 

For TRS-80 and North Star 
Computers 

SPACE FRAME (Finite Element - Stiffness Method) 
includes Space Frame, Plane Frame, Space Truss & Floor Grids 
Disk Version $ 1 50. DO Cassette Version $50.00 

TRS-80 Model II $200.00 Documentation Only $25.00 

plus postage 

TRUSS FORCE (Method of joints solution of Common Trusses) 

Oisk Version $50.00 Cassette Version $25.00 

Documentation Only $5.00 plus postage 

LINEAR PROGRAMMING (Simplex Method) 

Disk Version $60.00 Cassette Version $25.00 

Documentation Only $5.00 plus postage 

ENGINEERING ANALYSIS 
SOFTWARE 

P.O. Box 26206 
Fort Worth, Texas 76116 
Phone 1214) 298-1248 
In California Contact: 

MICOPS INC. 

421 Royale Park Dr. 

San Jose, Ca. 95136 

Phone (408) 629-5716 



FIELD ENGINEERS 

TECHNICAL SUPPORT 

FIELD SERVICE MANAGEMENT 

SYSTEMS 370/360, H-200, 
XDS, Univac, CDC 
All large & medium CPU's 

MINI'S PDP, NOVA, G.A., HP, 

etc... All Mini Systems 

I/O STC, TELEX, CDC, ITEL, 

CALCOMP, etc... All 
Peripheral Experience. 

SPECIALIZED PLACEMENT OF THE 
FIELD SERVICE PROFESSIONAL 

LET US LOCATE THE BEST OPPORTUNITIES 
FOR YOU 

NATION WIDE 

I IE 1 1 MUI W Silllnjrw 

925 E. RAND RD. 

ARLINGTON HEIGHTS, ILL 60004 

(312) 398-5535 

Private Employment Agency — no fees 



NOBLE 



COMPUTER CORPORATION 

ADD the ultimate to your computer system 

"SOUND" 

106,000,000 Distinct Sounds 

Noble Computer Corporation announces the 
development and production of a computer 
SOUND board, for S-100 or S-50 Bus User 
complete with software, capable of producing 
106 Million distinct sounds. 

Also available - S-50 INTERFACE 

Open up your computer system to the real 
world. Now at last there is an S-50 to S-100 in- 
terface available that allows you to be com- 
patible with any S-100 Bus interface system, 
I/O media or memory system. This third 
generation S-50 Bus interface features: 

• Selectable memory addressability 

• Selectable I/O Device Addressability 

• Up to 64K Addressability 

Both products are assembled, tested, and 
guaranteed: 

Computer Sound Board - $179.95 
S-50 to S-100 Interface - $129.95 



Circle 281 on inquiry card. 



Circle 282 on inquiry card. 



DAL - COMP 



DAL-COMP gives you the finest lines in electronic hardware, components, computer boards and peripherals. 



SD SYSTEMS 

FOR S- 100 

Memory Boards, Video Boards, CPU Boards, 
PROM Boards, Single Board Computers, Control- 
ler Boards, Software. 

SSM 

FOR S- 100 — APPLE 

Video Boards, IO Boards, Music Boards, CPU 
Boards, RAM Boards, EPROM Boards, Extender 
Boards, Terminator Boards. 

AP PRODUCTS 

Solderless Plug Boards, Bread Boards, Flat Ribbon 
Cable Assemblies, Jumper Headers, Test Clips, 
Connectors, Sockets. 



CALIF. COMPUTER SYSTEMS 

FOR S- 1 00 — APPLE — TRS 80 

Interface Boards, PROM Boards, Controller 
Boards, CPU Boards, RAM Boards, Mainframes, 
Extender Boards, Proto Boards. 

QT COMPUTER SYSTEMS 

FOR S- 100 

Memory Boards, CPU Boards, Clock Calendar, 
Motherboards, I/O Boards, Video Boards, EPROM 
Boards, Controller Boards. 

MOUNTAIN HARDWARE 

FOR APPLE 

Introl X- 1 0, Apple Clock, Super Talker, ROM Wri- 
ter, ROM Plus, Music System, A/D 8. D/A, Expan- 
sion Chassis. 



— PANAVISE — OK MACHINE &. TOOL — MODEMS — EPROM ERASERS — DISKS — DISK DRIVES — POWER 
SUPPLIES — VECTOR ELECTRONICS — IC's — (TTL — CMOS — MEMORY) — SOCKETS — SWITCHES — 
TERMINALS — 



Call Dal-Comp for prices on all your electronic and computing needs. We offer the finest products in the 
industry at prices you can compare with anyone. Check our fast service and responsive sales people. 



| CALL TOLL FREE 800-527-5310 



TEXAS RESIDENTS 

CALL COLLECT (214) 350-6898 



THIS MONTH'S SPECIAL 


4116 250NS 


8/$48.00 


2114L300NS 


5.25 


DB25P Male Plug 


2.95 


2708 


6.25 


2114L.450NS 


5.00 


DB25S Female Socket 


3.60 


2716 


19.95 


1771 


26.95 


DB25C Cover 


1.50 


2732 


79.95 


1791 


37.95 


RS232 Set/1 Ea of above 6.50 


8080A 


3.50 


1863/AY51015 


5.95 


UV Eraser 


68.95 


Z80A 


13.95 


1602B 


3.95 


Dip Switches 


Call 


8253-5 


20.25 


S-2350 


7.95 


Zip Dip Sockets 


Call 


8279-5 


18.50 


8212 


3.50 


Lo-Pro Sockets 


Call 



ofjrv 



u**- 



CO** 



TERMS OF SALE: Cash, checks, money orders. VISA. Master Charge Minimum Order $10.00. Texas residents add 5% sales tax. Minimum shipping and handling 
charge S3 00. COD orders add S2 00 COO tee U.S. funds only PRICES SUBJECT TO CHANGE WITHOUT NOTICE, SOME ITEMS SUBJECT TO PRIOR SALE, WE 
RESERVE THE RIGHT TO LIMIT QUANTITIES 90 DAY GUARANTEE 

DAL-COMP M/0 DIV. 2560 ELECTRONIC LANE, SUITE 108, DALLAS, TEXAS 75220 • (214) 350-6895 



Circle 284 on inquiry card. 



BYTE August 1980 293 



H89/H8/Z89 

Software Tools That Work 
PIEt full screen editor $29.95 

TEXT formatter 34.95 

(order both for word processing) 
C Compiler* 39.95 

Airport (real-time game) 19.95 
File packer, modem/ file-transfer, 
LISP interpreter, Z80 & 8080 
macro assemblers, more. 
Quality software running under 
HDOSt (requires 32K RAM). 
Available at Heathkitt stores or 
Walt Bilofsky's 
Software Tool Works 
14478 Glorietta Drive 
Sherman Oaks, CA 91423 
Phone orders: (213) 986-4885 

Add $2/order 1st class postage and handling. 
CA residents add 6% sales tax. 
'Documentation complements The C Program- 
ming Language, Kernighan & Ritchie. 
tHeathkil, HDOS: TM of Heath Company. 
PIE; TM of Programma International, Inc. 



STANDARD 
fig-FORTH 



A/FORTH 

FOR THE @ 

ALPHA MICRO 

PROFESSIONAL 

MANAGEMENT 

SERVICES 

724 Arastradero Rd., Suite 109 

Palo Alto, California 94306 

408/252-2218 

® A REGISTERED TRADEMARK OF 
ALPHA MICRO SYSTEMS 



SUPPLIES 




• 3M DISKETTES, MINI OR 

STANDARD 

• 3M DATA CARTRIDGES, 

CASSETTES, DISK PACKS 

• RIBBONS, PRINT WHEELS, 

ELEMENTS, PAPER 

^X ZAPP >> 

STATIC PROBLEMS??? 

CALL US ON 3M VELOSTAT® 

ANTISTATIC FLOOR MATS 

5555 Magnatron Blvd. ttJ 
San Diego, CA92111 
(714) 565-4505 



BUSINESS SYSTEMS. INC 



Circle 285 on inquiry card. 



Circle 286 on inquiry card. 



Circle 287 on inquiry card. 



Z-80 

***** TESTING/INPUT-OUTPUT ***** 

PACKAGE 

(Primarily for NORTH STAR DOS users who develop 
assembler or machine language programs) 
Featuring: 

(A) Integrated Testing Package 

• Full instruction trace 

• Breakpoint 

• Display/alter RAM contents 

(B) Input - Output Package, designed to be called by 

assembler-oriented programs 

• Random or sequential access to 
diskette files 

• Record blocking/deblocking with se- 
quential 

• Console input-output assist 

• Data compare and set return codes 

Both for $45 on single density 5" diskette, ppd. 

Requires 4K beginning at location zero 

Test Package may be interfaced to other Z-80 

systems 
l-O Package supports single or double density 
Full documentation and source included. 

Code Construction Co., 

P.O. Box 235 

Wentzville, Missouri 63385 

P.S Cross-Pack Catalog Lister 

(One listing for all your packs— computes free space) 

$10 with Testing/l-0 Package 



FOR SALE BY OWNER: 
MUST SELL! 

Pertec, MITS 300 

Complete Small Business System . . . 

or will consider selling components 

Altair 8800BT 

64 K static RAM 

10 Mb Pertec top load hard disk 

Qume 45-cps letter quality printer 

Lear-Siegler ADM3A CRT 

Rack-mount desk 

Plus: Microsoft BASIC, utility programs, 
Word Processing, spare 16K, memory test 
routines in ROM, up to twenty 3M Disks. 
Used 24 mo., now in operation. 
Available 8/15. 

Steve Livers 
215-657-6575 
LA Assoc'd, Inc. 
Willow Grove (Phila), PA. 



ALL CP/M & CROMEMCO SYSTEMS 

INVENTORY CONTROL [lor MannlKturtri & Retailers) S250 

Parts explosions lor finished goods & assemblies 

Parts requirements forecasting & Pull Sheets 

Economic Order Quantities & Reorder Reports 

1500 items per S.D. 8" disk side 

ACCOUNTS PAYABLE/RECEIVABLE SI 75/S1 75 

Replaces all your hand written ledgers 

Prints Monthly Ledger Sheets, Checks, Vouchers & Stubs 

Aged Trial Balances & Statements 

Handles Discounts, Partial Payments, Credits, Etc, 

APARTMENT MANAGEMENT SYSTEM S250 

Prints all your Monthly Rent Bills 

Reports Late Payments, Vacancies, and Lease Expirations 

Links with Accounts Receivable Program 

PAYROLL SYSTEM SI 75 

300 Employees per S.D. 8" disk side 

Federal, State and Local Taxes 

Quarterly & Yearly Reports (inc. 941 s & W-2's) 

Prints Payroll Registers, Checks & Vouchers 

MAILING LIST S99 

Maintains your list up to 1 700 customers per S.D. 8" disk side 

Prints the list by Customer Type. City. State or Zip 

Can be used to send Personalized Form Letters 

These programs run FASTER & BETTER than ones costing up to 5 

times more All used over 1 ft years by several large corporations 

Hardware Required: 48 KRAM, dual floppy disks,132 col printer. 

Written in Cromemco 16 K EXTENDED BASIC (runs under CP/M) 

FEITHSOFTrlMiE 

Cldirbnrok A-1103 
Wyncoti. Pi. 19095 
(21 5| BB7-97B0 



Circle 288 on inquiry card. 



Circle 289 on inquiry card. 



Circle 290 on inquiry card. 



WISCONSIN AREA 
■COMPUTER CO. 



"jJSavi *ptU( Semite 



7&f%& 



vns-Kztis spzew-ds 



10 Vv&uo* VCM 26.40 



10 tfmUttm S.S. 



*29.00 



Mail Orders or Send for Brochure : 
WISCONSIN AREA (COMPUTER CO. 
1328 BALSAM PLACE 
WEST BEND, WISCONSIN S3095 

Wisconsin Residents Add 47. Sales Tax 
Add 5'/. for Shipping & Handling 



MINI FLOPPY SALE 



TRS-80 OWNERS 
SINGLE SIDED $365.00 
DOUBLE SIDED $485.00 
READY TO GO- CABINET- 
POWER SUPPLY-CABLE 
ASSEMBLED § TESTED 



ADD ON DRIVES 
SINGLE SIDED $225.00 
DOUBLE SIDED $ 345.00 



INTERFACE, INC. 
20932 CANTARA STREET 
CANOGA PARK,CA. 91304 
(213) 341-7914 

MASTER CHARGE f, VISA 



MARKET DATA LISTINGS 

14 COMMON STOCKS 

A DAILY CLOSE 81 VOLUME 
Feb. 28, 1978 to present 

A FOR THESE STOCKS 

ASA BallyMfg HughsTI 
AllisCh CornG IBM 
AHess EsKod LeviStr 
ABdcst GMot Nwtlnd 
Avon Honwll 

$20 Each, $160 Lot - LISTS 

/\/\dd $30 Per Lot For Diskette 

IBM 8" 2D (IBM 5120 BASIC) 
NORTH STAR BK" (N.S. BASIC) 
MC, VISA, CHECK, MONEY ORDER 








V\A H 1 MARKET 

SJ V \,J V 1 ANALYSIS 






POST OFFICE BOX 415 
BURLINGTON. IOWA 52601 



Circle 291 on inquiry card. 



Circle 292 on inquiry card. 



Circle 293 on inquiry card. 




computer 
products, inc. 



11542-1 KNOTT ST. 

GARDEN GROVE, 

CA 92641 

(800)854-6411 

(714)891-2663 



IMSAI CONN, 

100 PIN GOLD 
SOLDERTAIL 



4116'S -200NS. 

ADD-ON MEMORY FOR: 

APPLE, TRS-80, HEATH, 

EXIDY, SD. EXPANDORAM. 

8for $ 49 95 

16for s 95 00 



ATARI 400 & 800 



MICR0BYTE 



CAPACITORS 

.1® 12 VOLTS 

CERAMIC 



MODEL 400 

Computer Console 
Basic Language 
Cartridge 
Basic Language 
Programming Manual 
Operators Manual 
Power Supply 
TV Switch Box 

CALL FOR 
PRICE 

AVAILABLE 
FROM STOCK 



SHUGART 



SA801R 

Bare Drives 

Single Sided/ 

Sgl/Dbl Density 

CALL FOR PRICE 

AND 

DELIVERY 



LINEAR COMPONENTS 



MODEL 800 

• Computer Console 

• Basic Language 
Cartridge 

• Education System 
Master Cartridge 

• Basic Language 
Programming Manual 

• Operators Manual 

• Atari 410 Program 
Recorder 

• Guide to Basic 
Programming Cassette 

• 8K Ram Module 

• Power Supply 

• TV Switch Box 



SPECIAL 



Ani/STATIC 
OLA RAM BOARD 

• IEEE/S-100 

• 4K Bank Addressable 
to any 4K Slot within 
a64K Boundary 

• On-board 8-Bit 
Output Port 

• No DMA Restrictions 

• Assembled & Tested 

• 4MHz Operation 

$49 oo 

SANYO 

B&W 
MONITORS 
9" MODEL 

$ 175 oo 

15" MODEL 

$250 00 



110 



or 



100 for $10.00 



SA800 DISK DRIVES 

SHUGART 8" SGL SIDED/DBL DENSITY 

DISK DRIVE, WITH CABINET, PWR. SUPPLY. 

(ASSEMBLED & TESTED) 

(1 ) DRIVE INSTALLED (2) DRIVES INSTALLED 

$77500 s 1250 00 



2114's 

(200NS.) 
LO-POWER 

$ 4 75 ea. 

(1-49) 
50&up $4.35 ea. 



LM 348 75 

LM 377 90 

LM 555 35 

LM3900 42 



2716'S 

5-VOLT ONLY 
(450 NS) 

S 25°Pa. 

HITACHI, FUJITSU 



STATIC & DYNAMIC 
RAM CHIPS 



2104 

(4K Dynamic) s 2 25 ea . 

4108/4115 t!Mnn 
(8K Dynamic) $ 4°ea. 

5257-3L 

(4K Static) $5 5 e °a. 

250 NS 



LOBO INTERNATIONAL * 



MICROBYTE 



16K 



STATIC 
RAM BOARD 



INTEL'S $30.00 



SHUGART SA400 

• Enclosed in Metal Case 

• Cutouts for Data Cable, 
Switch, Fuse & Pwr Cord 

$31 500 



TRS-80 DISK DRIVES 



Shugart SA400, Single or Double Density, 
Soft Sector, up to 218K Bytes, 25 MSec. 
Access Time, Software Compatible. 

539500 



REGULATORS 



320T-5 90 

320T-12 80 

340T-5 75 

340T-12 65 

78H05 5.25 



ORDERING INFO 



Name, Address, Phone 
Ship by: UPS or Mail 

Shipping Charges, Add 
$2.00 up to (5) lbs. 



TERMS 



We Accept Cash, 
Check, Money Order, 
Visa & Master Charge. 
C.O.D.'s on Approval. 

(U.S. Funds Only) 

Tax: 6% Calif. Res. 



CATALOG 

AVAILABLE 

CALL 

OR 

WRITE 



TRS-80 EXPANSION 
(LX-80) INTERFACE 

• CONNECTS DIRECTLY 
TO KEYBOARD 

• TO SERIAL PORTS 

• PARALLEL PORT FOR 
PRINTER, PLUS MANY 
MORE OPTIONS. 

$49300 



CENTRONICS 
PRINTERS 

(MODEL #703) 

• 180 CPS BI-DIRECTIONAL 

• LOGIC SEEKING PRINTER 

• 132 COLUMN CARRIAGES 

• VFud CENTRONICS 
PARALLEL INTERFACE 

$ 1850 00 



S-1 00 Compatible 
4K Bank Addressable 
Extended Memory 
Management 
No DMA Restrictions 
Assembled & Tested 
4MHz Operation 

$250»° 



74LS244 



QTY. PRICES AVAILABLE 



CENTRONICS 

MODEL 

#737 

PRINTER 

(IN STOCK) 



LO-PRO SOCKETS 



14 PIN 
16 PIN 
18 PIN 
20 PIN 
24 PIN 
28 PIN 
40 PIN 



00 



1-99 
.10 
.12 
.15 
.23 
.26 
.30 
.42 



100 UP 
.09 
.11 
.13 
.21 
.24 
.28 
.40 



825 



2708's 

(450 NS) 

00 

i ea. 

or 

8/ $ 58 



Circle 294 on inquiry card. 



BYTE August 1980 295 



CD4000 
CD40Q1 
CD40O2 
CD4Q06 
CD4007 
CD40O9 
CD4010 
CD4011 
CD4012 
CD4013 
CD4014 
CD4015 
CD4016 
CD4017 
CD401B 
CD4019 
CD4Q20 
CD4021 
CD4022 
CD4023 
CD4024 
CD4025 
CO4026 
CD4027 



74COO 
74C02 
74C04 
74C08 
74 CIO 
74C14 
74C20 
74C30 
74C42 
74C4B 
74C73 
74C74 



.89 



78MG 1.75 

L.M106H .99 

LM3O0H .80 
L.M301CN/H .35 

LM302H .75 

LM304H 1.00 

LM305H .60 
LM307CN/H .35 
LM308CN/H 1.00 

LM309H 1.10 

LM309K 1.25 

LM310CN 1.95 

LM311N/H .90 

LM312H 1.95 

LM317K 6.50 
LM318CN/H1.50 

LM319N 1.30 

LM320K-5 1.35 

LM320K-5.2 1.35 

LM320K-12 1.25 

LM320K-15 1.35 

LM320K-18 1.35 

LM320K-24 1.35 

LM320T-5 1.25 

LM320T-5.2 1.25 

LM320T-8 1.25 

LM320T-12 1.25 

LM32QT-15 1.25 

L.M320T-18 1.25 

LM320T-24 1.25 

LM323K-5 5.95 

LM324N 1.49 

LM339N .99 

LM340K-5 1.35 

LM340K-* 1.35 

LM34QK-B 1.35 

L.M340K-12 1.35 

LM340K-15 1.35 



7400 TTL 

SN7470N .29 

SN7472N .29 

SN7473N .35 

SN7474N .35 

SN7475N .49 

SN7476N .35 

SN7479N 5.00 

SN74B0N .50 

SN7482N .99 

SN7483N .69 

5N7485N .89 

SN7486N .35 

SN7489N 1.75 

5N7490N .45 

SN7491N .59 

SN7492N .43 

SN7493N .43 

SN7494N .65 

SN7495N .65 

5N7496N .65 

SN7497N 3.00 

SN74100N 1.25 

SN74107N .35 

SN74109N .59 

SN74116N 1.95 

SN74121N .35 

SN74122N .39 

SN74123N .59 

SN74125N .49 

SN74126N .49 

SN74132N .75 

SN74135N .75 

5N74141N .79 

SN74142N 2.95 

SN 74143 N 2.95 

SN74144N 2.95 

SN 74145 N .79 

5N74147N 1.95 

SN7414BN 1.29 

5N741S0N 1.25 

SN74151N .59 

SN74152N .59 

SN74153N .59 

SN74154N 1.50 

SN74155N .79 

5N74156N .79 

SN74157N .65 



SN74160N .89 

SN74161N .89 

SN74162N 1,95 

SN74163N .89 

SN74164N .89 

SN74165N .89 

SN74166N 1.25 

SN74167N 1.95 

SN74170N 1.59 

SN74172N 6.00 

SN74173N 1.25 

SN74174N 1.00 

SN74175N 1.00 

SN74176N .79 

SN74177N .79 

SN74179N 1.95 

SN74180N .79 

SN74181N 1.95 

5N74182N .79 

SN74184N 1.95 

SN74185IM 1.95 

SN74186N 9.95 

SN74188N 3.95 

SN74190N 1.25 

SN74191N 1.25 

SN74192N .79 

SN74193N .79 

SN 74194 N .89 

SN74195N .69 

SN74196N .89 

SN74197N .89 

SN74198N 1.49 

SN74199N 1.49 

SN74S200 4.95 

S N 74251 N .99 

SN74279N .79 

SN74283N 2.25 

SN74284N 3.95 

SN74285N 3.95 

SN74365N .69 

SN74366N .69 

SN74367N .69 

SN74368N .69 

SN74390N 1.95 

SN74393N 1.95 



CMOS 



CD4028 
CD4029 
CD4030 
CD4035 
CD4O40 
CD4041 
CD4042 
CD4043 
CD4044 
CD4046 
CD4047 
CD4048 
CD4049 
CD4050 
CD40S1 
CD4053 
CD4056 
CD4059 
CD4060 
CD4066 
CD406B 
CD4069 



1.79 

2.50 
1.35 



1.19 
1.19 

2.95 



CD4070 

CD4071 

CD4072 

CD4076 

CD4081 

CD4062 

CD4093 

CD409B 

MC 14409 14.95 

MC14410 14.95 

MC14411 14.95 

MC14419 4.95 

MC14433 13.95 

MC 14506 .75 

MC14507 .99 

MC14S62 11.95 

MC 14583 

CD4508 

CD4510 

CD4S11 

CD4515 

CD4518 

CD4S20 

CD4566 



1.19 



3.95 



2.95 
1.29 
1.29 
2.25 



74CO0 



74C85 
74C90 
74C93 
74C95 
74C107 
74C151 
74C154 
74C157 
74 C 160 
74 C 161 



2.90 
3.00 
2.15 



74C163 

74C164 
74 C 173 
74 C 192 
74C193 
74 C 195 
74C922 
74C923 
74C925 
74C926 
80C95 
80C97 



6.25 
B.95 
8.95 
1.50 
1.50 



LINEAR 

LM340K-18 1.35 

LM340K-24 1.35 

LM340T-5 1.25 

LM340T-* 1.25 

LM340T-8 1.25 

LM340T-12 1.25 

LM340T-15 1.25 

LM340T-18 1.25 

LM340T-24 1.25 

LM35BN 1.00 

LM370N 1.95 

LM373N 3.25 

LM377N 4.00 

LM380N 1.25 

LM380CN .99 

LM381N 1.79 

LM382N 1.79 

NE501N 8.00 

NE510A 6.00 

NES29A 4.95 

NE531H/V 3.95 

NE536T 6.00 

NE540 6.00 

NE544N 4.95 

NE550N 1.30 

NE555V .39 

NE556N .99 

NE5G0B 5.00 

NE562E3 5.00 

NES65N/H 1.25 

NE566CN 1.75 

NE567V/H .99 

NE570N 4.95 
LM703CN/H .69 

LM709N/H .29 



LM710N .79 

LM711N .39 

LM723N/H .55 

LM733N 1.00 

LM739N 1.19 
LM741CN/H .35 
LM741-14N .39 
LM747N/H .79 
LM748N/H .39 

LM1310N 1.95 
LM1458CN/H .59 

MC1488N 1.95 

MC1489N 1.95 
LM1496N .95 

LM 1556 V 1.75 

MC1741SCP 3.00 

LM2U1N 1.95 

LM2901N 2.95 

LM3053N 1.50 

L.M3065N 1.49 
LM 3900 N (3401). 59 

LM3905N 1.49 

LM3909N 1.25 
MC5558V .59 

8038 B 4.9S 
LM75450N .49 
75451CN .39 

75452CN .39 

7S453CN .39 

75454CN .39 

7549 1CN .79 

75492CN .89 

75493 N .89 

75494 CN .89 

RC4136 1.25 

RC4151 3.95 

RC4194 4.95 

RC4195 4.49 



JE6Q8 PROGRAMMER 

2704/2708 EPROM PROGRAMMER 




• 3 UPl'ltt Oiiplif ll( 5 .ittn S LED'iioi Hn Kty flntt. ID LED 
lor Addr.ii RrgiiliiKirJl LEO'llor DitiMimoiy RigiiKi. The Oil 
H>|littf diujliyi itii unlint si I hi RAMi I mm ih< EPHDM Chls. 

B'omirnnur ptml tail ucWtl la Ih. EPROM locfctl on Ihi until 



"t>r«jriram<r confining si: 
A IS >iy HlIIOKlmilKEyboiidnumblv. PiojnmiTi.r Band ■ iirmbty with 
i powir wpplHi md • LED/I ra Sockn panel Board numbly. Tho Tm 
SDlktl nicroloro mini. on lypi. ponci rtqyir.cii.nu 1 IBVAC. 6HH*. 6rt. 



a LED.'Tbsi Socki-i I'j-i,.-I tSo.) 



JE608 KIT $399.95 

JE608 Assembled and Tested $499.95 






74LS0O 
74LS01 
74LS02 
74LS03 
74LS04 
74LS05 
74LS08 
74LS09 
74LS10 
74LS11 
74 LSI 3 
74LS14 
74LS15 
74LS20 
74LS21 
74LS22 
74LS26 
74LS27 
74LS28 
74LS30 
74LS32 
74LS37 
74L.S40 
74LS42 
JLS47 



74LS00TTL 

74LS51 
74LS54 
74LS55 
74LS73 

74LS74 
74LS7S 
74LS76 
74 L 578 
74LSB3 
74LS85 
74LS86 
74LS90 
74LS92 
74LS93 
74LS95 
74LS96 
74LS107 
74LS109 
74LS112 
74LS123 
74LS125 
74LS132 
74LS136 
74LS138 



74L.S139 
74LS161 
74LS155 
74LS157 
74LS160 
74LS161 
74LS162 
74LS163 
74LS164 
74LS175 
74LS181 
74LS190 
74LS191 
74LSI92 
74LS193 
74LS194 
74LS195 
74LS253 
74LS257 
74LS258 
74LS260 
74LS279 
74LS367 
74LS368 
74LS670 



DISCRETE LEDS 



XC556R .2X" red 

XC556G .200" green 

XC556Y .200" yellow 

XC556C .200" clear 

XC22R .200" red 

XC22G .200" green 

XC22Y .200" yellow 

MV10B .170" red 



5/$l 
4/$l 
4/$l 
4/$l 

5/S1 
4/S1 
4/S1 
4/$l 



MV50 .085" red 
XC209R .125" red 
XC209G .125" green 



6/51 
S/Sl 
4/$l 



XC209V .125" yellow 4/J1 



XC526R .185" 
XC526G .185" green 
XC526Y .185" yellov 
XC526C .185" clear 



5/J1 
4/S1 

4/$l 
4/$l 



XC111R .190" red 5/S1 

XC111G .190" green 4/$l 

XC111Y :i90" yellow 4/J1 

XC111C .190" clear 4/S1 



INFRA-RED LED 
■x V> M xl/16" flat 5/$l 



DISPLAY LEDS 



TYPE 

MAN 1 
MAN 2 
MAN 3 
MAN 4 
MAN 7G 
MAN7Y 
MAN 72 
MAN 74 
MAN 82 
MAN 84 
MAN 3620 
MAN 3630 
MAN 3640 
MAN 4610 
MAN 4640 
MAN 4710 
MAN 4730 
MAN 4740 
MAN 4810 
MAN 4840 
MAN 6610 
MAN 6630 
MAN 6640 
MAN 6650 
MAN 6660 
MAN 6680 
MAN 6710 



POLARITY I 

Common Anode-ted 
5 x 7 Dol Matrix-red 
Common Caihode-red 
Common Calhode-red 
Common Anode-grwn 
Common Anode-yellow 
Common Anode- red 
Common Calhode-red 
Common An ode -yellow 
Common Catfi ode -yellow 
Common An ode -orange 
Common Anode-orange = 1 
Common Cathode-orange 
Common Anode-orange 
Common Calhode -orange 
Common Anode-red 
Common Anode-red ± 1 
Common Calhode-red 
Common Anode-yellow 
Common Cathode -yellow 
Common Anode-orange-D.O. 
Common Anode-orange ± 1 
Common Calhade-oranoe-D.D. 
Common Cathode -orange t 1 
Common Anode-orange 
Common Cathode-orange 
Common Anode-red-D.D. 



PRICE 

2.95 
4.95 



TYPE 

MAN 6730 

MAN 6740 

MAN 6750 

MAN 6760 

MAN 6780 

0L701 

OL704 

DL707 

DL728 

0L741 

OL746 

DL747 

DL749 

OL750 

DL33B 

FN070 

FND358 

FN0359 

FN0503 

FND507 

5082-7730 

HDSP-3400 

HDSP-3403 

5OB2-7300 

5082-7302 

5082-7304 

50B2-7340 



POLARITY 

Common Anode-red ± 1 
Common Calhodo-rBd-D.O, 
Common Calhode-red + 1 
Common Anode-red 
Common Calhode-red 
Common Anode-red * I 
Common Cathode-red 
Common Anode -red 
Common Calhode-ied 
Common Anode -red 
Common Anode-red ± I 
Common An ode -red 
Common Cathofle-ied ± 1 
Common Cathode- red 
Common Cathode -red 
Common Cathode 
Common Cathode • 1 
Common Cathode. 
Common Ca1hode(FND500) 
Common Anode (FND510) 
Common Anode-red 
Common Anode-red 
Common Cathode red 
4 x7 sgl. Digit-RHDP 
4 x 7 Sgl. Dlgit-LHDP 
Overrange character |--1) 
4x7 Sgl. Digit -Hexadecimal 



19.95 
19.95 
15.00 
22.50 



RCA LINEAR 



2.15 

3.25 
2.48 



CA3013T 
CA2023T 
CA303ST 
CA3039T 
CA3046N 1.30 
CA3059N 3.25 
CA3060N 3.25 
CA3080T 1.25 
CA3081N 2.00 



CA3082N 2.00 

CA3083N 1.60 

CA3066N .85 

CA3089N 3.75 
CA3130T 
CA3140T 
CA3160T 

CA3401N .59 

CA3600N 3.50 



1.25 



CALCULATOR 
CHIPS/DRIVERS 

MM 5725 $2.95 

MM5738 2.95 

DM8864 2.00 

DM8865 1.00 

DMB887 .75 

DM8889 .75 
9374 7-seg. 
LEO driver 1.50 

MMS309 4.95 



LOW PROFILE 

(TIN) SOCKETS 



8 pin LP 
14 pin LP 
16 Pin LP 
IB pin LP 
20 pin LP 
22 Pin LP 
24 pin LP 
28 pin LP 
36 pin LP 
40 pin LP 



SOLDERTA1L (GOLD) 
STANDARD 



8 pin SG 
14 pin SG 
16 pin SG 
IB pin SG 
24 pin SG 
28 pin SG 
36 pin SG 
40 pin SG 



CLOCK CHIPS 

MM5309 4.95 

MM5311 4.95 

MMS312 4.95 

MM5314 4.95 

MM5316 6.95 

MM 53 16 9.95 

MM5369 2.95 
MM5387/1998a4.95 

CT 7001 6.95 



MOTOROLA 



MC1408L7 
MC14Q8L8 
MC1439L 
MC3022P 
MC3061P 
MC4016 (74416)7.50 
MC4024P 3.95 
MC4040P 6.95 
MC4044P 4.50 



4.95 
5.75 
2.95 
2.95 
3.50 



SOLDERTAIL 

STANDARD (TIN) 



14 pin ST 

16 pin ST 
18 pin ST 
24 pin ST 
28 pin ST 
36 pin ST 
40 pin ST 



WIRE WRAP SOCKETS 
(GOLD) LEVEL #3 

1-24 25-49 50-100 



1.38 
1.79 
1.B9 



TELEPHONE/KEYBOARD CHIPS 

AY-5-9100 Push Button Telephone Dialler 

AY-5-9200 Reperto'y Dialler 

AY-5-9500 CMOS Clock Generator 

AY-5-2376 Keyboard Encoder (88 keys) 

HD0165 Keyboard Encoder fl6 keys) 

74C922 Keyboard Encoder (16 keys) 

74C923 Keyboard Encoder J20 keys) 



ICM7045 
ICM7205 
ICM7207 
ICM720B 
ICM7209 



ICM CHIPS 

CMOS Precision Timer 
CMOS LED Slopwatch/Timer 
Oscillator Controller 
Seven Decade Counter 
Clock Generator 



24.95 

19.95 
7.50 

19.95 
6.95 





NMOS READ ONLY MEMORIES 




MCM6571 


128 X 9 X 7 ASCII Shifted with Greek 


13.50 


MCM6574 


128 X 9 X 7 Mam Symbol S Pictures 


13.50 


MCM6575 


128X9X7 Alpha Control Char Gen 


13.50 



MISCELLANEOUS 

TL074CN Quad Low Noise bi-iet Op Amp Z.«9 

TL494CN Switching Regulator 4.49 

TL496CP Single Switching Regulator 1 .75 

11C90 Divide 10/11 Prescaler 19.95 

95H90 Hi-Speed Divide 10/11 Prescaler 11.95 

4N33 Photo-Darlington Opto-lsolator 3.95 

MK50240 Top Octave Freq. Generator 17.50 

DS0026CH 5Mhz 2-phase MOS clock driver 3.75 

TIL308 .27" red num. display w/inleg. logic chip 10.95 

MM5320 TV Camera Sync. Generator 14.95 

MM5330 4V> Digit DPM Logic Block (Special) 3.95 

LD110/111 3W Digit A/D Converter Set 25.00/set 

MC14433P 3'A Digit A/D Converter 13 95 



LITRONIX ISO-LIT 1 

Photo Transistor Opto-lsolator 

(Same as MCT 2 or 4N25) 

49°i each 



SN 76477 

SOUND GENERATOR 
Generates Complex Sounds 
Low Power - Programmable 

$3.95 each 



TV GAME CHIP AND CRYSTAL 

AY-3-8500-1 and 2.01 MHZ Crystal (Chip & Crystal _ n _ . . 
includes scoig display. G games auu seieel angles, etc. / . jO/S6l 



$8.40 
4.40 
4.40 
1.55 
1.50 



XR205 

XR210 

XR215 

XR320 

XR-L555 

XR555 

XR556 

XR567CP 

XR567CT 

XR1310P 

XR1466CN 3.85 

XR1488 195 

XR1489 1.95 



1.25 
1.95 



EXAR 



JE2206KB 19.95 
XR1800 3.20 
XR2206 4.40 
XR2207 3.B5 
XR2208 5.20 
XR2209 1.75 



XR2240 3.45 



XR2242CP 1.50 
XR2264 4.25 
XR2556 3.20 
XR2567 2.99 
XR3403 1.25 
XR4136 1.25 
XR4151 195 
XR4194 
XR4202 
XR4212 
XR4558 
XR4739 
XR4741 



us 

360 
2.05 
.75 
1.15 

1 47 



TYPE 

IN746 

IN75I 

1N752 

1N753 

1N754 

IN757 

1N759 

1N9S9 

1N965 

1fJ5232 

1N5234 

1N523S 

1N5236 

1NS242 

1N5245 

1N456 

1N458 

1N4B5A 

1N4001 



DIODES 

VOLTS W 

3.3 400m 

5.1 400m 
5.6 400m 

6.2 400m 
6.8 400m 
g.O 400m 

12.0 400m 

8.2 400m 

15 400m 

5.6 500m 

6.2 500m 

6.8 500m 

7.5 500m 

12 500m 

15 500m 



6/1.00 
6/1.00 

5/1.00 



1/4 WATT RESISTOR ASSORTMENTS -5% 



CAPACITOR 



5 OHM 18 OHM 22 OHM 

7 OHM 33 OHM 39 OHM 47 OHM 56 OHM 

8 OHM 82 OHM 100 OHM 1Z0 OHM 150 OHM 
OHM 720 OHM ?70 OHM 330 OHM 390 OHM 



-170 Ohm 560 OHM B8Q hum 820 OHM 



220K 
560K 



100K 
270K 
6S0K 
I.8M 



2.7K 
6.8K 



330K 
620K 
2.2M 

5.6M 



ASST. 8R Includes Resistor Assortments 1 -7 (350 PCS. 



50 PCS 


$1.75 


50 PCS 


1.75 


50 PCS 


1.75 


50 PCS 


1.75 


50 PCS 


1.75 


50 PCS 


1.75 


50 pes 1.75 
$9.95 ea 



$10.00 Min. Ordar - U.S. Funds Only Spec Sheets - 254 

Calif. Residents Add 6% Sales Tax 1980 Catalog Available - Send 41«! stamp 

Postage — Add 5% plus $1 Insurance (if desired) 

PHONE 

ORDERS 

WELCOME 

(415)592-8097 




ameco 



MAIL ORDER ELECTRONICS - WORLDWIDE 

1355SHOREWAY ROAD, BELMONT, CA 94002 
PRICES SUBJECT TO CHANGE 



TYPE 

1N4002 
1N4003 
1N40O4 
1N4005 
1N4006 
1N4007 
1N3600 
tN414B 
1N4154 
1N4733 
1N4734 
1N4735 
1N4736 
1N473B 
1N4742 
1N4744 
INI 183 
1N1184 
1N1185 
1N1186 
1N11B8 



VOLTS W 

100 PIV 1 AMP 
200 PIV 1 AMP 
400 PIV 1 AMP 
600 PIV 1 AMP 
BOO PIV 1 AMP 
1000 PIV 1 AMP 
50 200m 
75 10m 
35 10m 



PRICE 
12/1.00 

12/1.00 



6/1.00 
15/1.00 
12/1.00 



12 



50 PIV 35 AMP 
100 PIV 35 AMP 
150 PIV 35 AMP 
200 PIV 35 AMP 
400 PIV 35 AMP 



SCR AND FW BRIDGE RECTIFIERS 



C36D 

C36M 

2N2328 

MBA SB 

MDA 980-3 12Afr 200V 



40OV 
600V 
300V 



C106B1 

MPSA05 

MPSA06 

TIS97 

TIS98 

40409 

40410 

40673 

2N918 

2N2219A 

2N2221A 

2N2222A 

PN2222 Plastic 

2N2369A 

MPS2369 

2N2484 

2N2906 

2N2907 

2N2S25 
MJE2955 
2N3053 



.50 
.30 

5/1.00 
6/1.00 
6/1.00 



TRANSISTORS 



FW BRIDGE REG. 
FW BRIDGE REG. 



2N3055 

MJE3055 

2N3392 

2N3398 

PN3567 

PN3568 

PN3569 

MPS3638A 

MPS3702 

2N3704 

MPS3704 

2N3705 

MPS3705 

2N3706 

MPS3706 

2N3707 

2N3711 

2N3724A 

2N3725A 

2N3772 

2N3823 

2N3903 



5/1.00 
5/1.00 
3/1.00 
4/1.00 
4/1.00 
5/1.00 
5/1.00 
5/1.00 
5/1.00 
5/1.00 
5/1.00 
5/1.00 
5/1.00 
5/1.00 



2N3904 
2N3905 
2N3906 
2N4013 
2N4123 
PN4249 
PN4250 
2N4400 
2N4401 
2N4402 
2N4403 
2N44D9 
2N5086 
2N50B7 
2N5088 
2N5089 
2N5129 
PN5134 
PN513B 
2N5139 
2N5210 
2N5449 
2N5951 



4/1 00 
4/1.00 
3/1.00 
6/1.00 
4/1.00 
4/1.00 
4/1.00 
4/1.00 
4/1.00 
4/1,00 
5/1.00 
4/1 00 
4/1.00 



10 pf 
22 pi 
47 pf 
100 pf 
220 pi 
470 at 

,001ml 
.0022 
.0047ml 



50 VOLT CERAMIC 
0ISC CAPACITORS 
U KMJ2 iflg_: 
.05 .04 .03 .00 Vf 
.05 .04 .03 ,0047 M F 
.05 .04 .03 .OldF 
.05 .04 .03 .022nF 
047^F 



CORNER 



.05 .04 .035 

.05 .04 .035 



.05 .04 .035 



.1mF 



1 00 VOLT MTLAR FILM CAPACITORS 
.022ml 
047ml 



.01 mf 


.12 


10 


.07 


,22ml 


.33 .27 




+ 20% DIPPED TANTALUMS (SOLID! CAPACIT0F; 


1/35V 








1.5/35V 






.39 


.31 


.» 


2.2/35V 


.51 .41 




.39 


,31 


-Tit 


3.3/25V 


.53 .43 


33/35V 


.39 


.31 


.'A 


4.7.25V 


.63 .51 


47/35V 


.39 


Jl 


.25 


6.8/25V 


.79 .63 




.39 








1.39 1.12 


0/35V 








22/6 V 






MINIATURE ALUMINUM ELECTROLYTIC CAPACITORS 



.47/50V 

1.0/50V 

3.3/50V 

4.7/25V 

10/25V 

10/50V 

22/25V 

22/50V 

47/25V 

47/50V 

100/25V 

10O/5OV 

220/25V 

220/50V 

470/25V 

1 000/1 6V 

2200/1 6V 



.47/25V 

.47/50V 

1.0/16V 

I.0/25V 

1.0/50V 

4. 7/ 16V 

4.7/25V 

4.7/50V 

10/16V 

10/25V 

10150V 

47/50V 

100/16V 

100/25V 

10D;5tN 

220/16V 

470/25V 



296 BYTE August 1980 



Circle 218 on inquiry card. 




ULTRAVIOLET 
INTENSITY 



METER 



by BLAK-RAY 



TWO MODELS: 
LONGWAVE 

AND 
SHORTWAVE 




Meter consists of a sensor cell attached to 
a compact (3" x 3%" x 3"] metering unit. 
Can be hand-held or placed directly on 
surface for measuring. Can be used re- 
motely, while connected to a meter hous- 
ing by a 4-foot extension cord. Two 
models available - one for long wave 
and one for short wave ultraviolet. Read- 
ings are in microwatts per square centi- 
meter. Weight: 1 lb. 

Completely assembled (includes sensor 
cell, reduction screen, extension cord, 
contrast filter and certification report.) 

J-221 LONGWAVE &,..* .--. 

(300nm-400nm) $24Z.UU 

J -225 SHORT WAVE ^ 
(200nm-280nm) Jp^OU.UU 



CONTINENTAL SPECIALTIES 



f">» Proto Clips 

14-PIN CLIP PC-14 .... $ 4.50 

16-PIN CLIP PC-16 .... $ 4.75 

24-PIN CLIP PC-24 .... $10.00 

>»»'/> 40-PIN CLIP PC-40 .... $16.00 



Proto Boards 

PB-6 $17.95 

fjjSS PB-100 19.95 

"** PB-101 22.95 

jVTjA PB 102 26.95 

~ J tit\\ PB-103 44.95 

— * PB-104 55.95 

PB-203 99.95 

PB-203A 155.00 

PB-203A-KU . . . 131.00 





Jumbo 6-Digit Clock Kit 

* Four .6ifl"ht. and two -300"ht. 
common anode displays 

« Uses MM5314 clock chip 

* Switches tor hours, minutes and hold functions 

* Hours easily viewable to 30 feet 

* Simulated walnut case 

* 115VAC operation 

* 12 or 24 hour operation 

* Includes all components, case and wall transformer 
*S\ze: 6V« x3* x IV* 

JE747 $29.95 




. cath- 



T.es 



• Bright .300 hi. co 
ode display 

• Uiei MM5314 clock chip 

• Swltchei for noun, mlrv 
and hold model 

• Hri. eailly viewable to 20 ft 

• Simulated walnut cote 

• 115 VAC operation 

• 12 or 24 hr. oporatlon 



. . I componi 
wall transformer 



JE701 

• Size: 6M" x 3-1/B" x 1 W" 

6-Digit Clock Kit $19.95 



Regulated Power Supply 



Uses LM309K. Heat sink ^*<C^ 
provided. PC board con- — 
struction. Provides a solid 
1 amp @ 5 volts. Can supply up 
to x5V, ±9V and ±12V with 
JE205 Adapter. Includes compo- 
nents, hardware and instructions. 
Size: 3'/ a " x 5" x 2"H 

JE200 $14.95 





ADAPTER BOARD 
-Adapts to J E 200- 
±5V, ±9Vand ±12V 



DC/DC converter with +5V input. Toriodal hi- 
speed switching XMFR. Short circuit protection. 
PC board consA*VKA\on. P^g^-back to JE 200 
board. Size: 314" x 2" x 9/16"H 

JE205 $12.95 



MICROPROCESSOR COMPONENTS 



B212 
8214 
6216 
8224 
8226 
8226 
8238 
8251 
8253 
8255 
8257 
6259 




-B0B0A/8080A SUPPORT DEVICES- 
CPU 

B-Bil Inpui/Ouiput 
Priority Interrupt Control 
Bi-Dirsclional Bus Oliver 
Clock Generator/Driver 
Bus Driver 

System Controllor.'Bus Driver 
System Controller 
Prog. Comm. 1/0 (USABT) 
Prog, interval Timer 
Prog. Periph 1/0 (PPI) 
Prog. DMA Control 
Prog. Interrupt Control 
B800/6BO0 SUPPORT DEVICES — 
MPU 

MPU with Clock aid Ram 
128X8 Sialic Ram 
Pe/lph Inter. Adapt (MC6820) 
Priority Interrupt Controller 
1024X8 Bit ROM (MC68A30-BJ 
Asynchronous Comm. Adapter 
Synchronous Serial Data Adapt. 
0-600 ops Digital MODEM 
2400 bps Modulator 
Quad 3-State Bus. Trans (WC8T26) 



-MICflOPROCESSOR MANUALS - 



M-280 User Manual 

M-C0P1B02 User Manual 
M-2650 User Manual 



-ROM'S - 



2513(21-10) Character Generator!^ ppcr case) 

2513(3021) Character Generatoi(lower case) 

2516 Character Generator 

MM5230N 2048-Bit Read Only Memory 



9.95 
12.95 
14.95 

2.25 



MICROPROCESSOR CHIPS— MISCELLANEOUS - 

280I780C) CPU 
Z80A|780-1) CPU 
CDP1602 CPU 
2650 MPU 

6502 



MM500H 

MM503H 

MM5WH 

MM50GH 

MM510H 

MM5016H 

25WT 

2518 

2522 

2524 

2525 

2527 

2528 

2529 

2532 

3341 

74LS670 



B-BilMPU w/clock, RAM, WO linos 

CPU 

16-Bit MPU w.n.irdwarc. multiply 

& divide 

SHIFT REGISTERS 

Dual 25 Bit Dynamic 

Dual 50 Bit Dynamic 

Dual IE Bit Static 

Dual 1C0 Bil Sialic 

Dual 64 Bit Accumulator 

500/512 Bit Dynamic 

1024 Dynamic 

Hex 32 Bit Static 

Dual 132 Bil Static 

512 Static 

1024 Dynamic 

Dual 256 Bit Static 

Dual 250 Static 

Dual 240 Bil Static 

Quad BO Bit Static 

Rto 

4X4 Register File (TriState) 



513.95 
15.95 

19.95 
19.95 
11.95 
19.95 
19,95 

49.95 



1101 
1103 

21Q1(B101) 

2102 

21L02 

2)11(8111) 

2112 

2114 

2114L 

2114-3 

2114L-3 

5101 

5280/210? 

7489 

74S200 

93421 

UPD<14 

(MK4027) 
UPDJ1G 

(MK4116) 
TMS4Q44- 

45NL 
TMSJ045 
2117 



256X1 

1024X1 

256X4 

1024X1 

1024X1 

256X4 

256X4 

1024X4 

1024X4 

1024X4 

1024X4 

256X4 

4096X1 

16X4 

256X1 

256X1 

4K 



1.80 MM5262 



1702A 
2716INTEL 

TMS251G 
[2716) 
TMS2532 
2708 
2716 T.I 



- RAM'S 

Sialic 

Dynamic 

Static 

Static 

Static 

Static 

Static MOS 

Static 450ns 

Static 450ns low power 

Static 300ns 

Static 300ns low power 

Static 

Dynamic 

Static 

Static Tristate 

Static 

Dynamic 16 pin 

Dynamic 16 pin 250ns 

Static 

Static 

Dynamic 350ns 
(house marked) 
Dynamic 

- PROM'S 

FAMOS 
EPR0M 
EPR0M 



11.49 

.99 
3.95 



7 95 
10.95 
10.95 
11.95 



2048 

6301-1(7611) 1024 
6330-1(7602) 255 
B2S23 32X8 

82S115 4096 

82S123 32X8 



16K' 
16K' 

■Requires single + 5V power supply 
4KX8 EPRDM 

BK EPR0M 

16K** EPR0M 

Requires 3 voltages. 



55,95 
59.95 
24.95 



A-Y-S-1013 30K BAUD 



FAMOS 

Tristate Bipolar 

Open C Bipolar 

Open Collector 

Bipolar 

Tristate 

TTL Open Collector 

TTL Open Collector 

Static 



2V 



14.95 
3.49 
2.95 



Function 
Generator Kit 




Provides 3 basic 
waveforms: sine, 
triangle and square 
wave. Freq, range 
from 1 HztolOOK 
Hz. Output ampli- 
tude from O volts 
to over 6 volts 
(peak to peak). 
Uses a 12V supply 
or a :6V split sup- 
ply. Includes chip, 
P.C. Board, com- 
ponents & instruc- 
tions. 



JE2206B $19.95 



DIGITAL 
THERMOMETER KIT 




■ Dual sensors— switching control for In- 
door/outdoor or dual monitoring 

• Continuous LED .8" ht. display 

• Range: -40°F to 199°F / -40°C to 100°C 
•Accuracy: ±1° nominal 

■Sot for Fahrenheit or Celsius reading 
"Sim. walnut case - AC wall adapter incl. 

• Sire; 3-1/4"Hx6-5/8"Wx1-3/B"D 

JE300 $39.95 



DESIGNERS' SERIES 
Blank Desk-Top Electronic Enclosures 

• High strength epoxy molded 
mid pieces in mocha brown 
finish. 

• Sliding rear/bottom panel for 
service and component ac- 
cessibility. 

• Top/bottom panels .080 thk 
alum. Alodine type 1200 
finish (gold tint color) for 
host paint adhesion after 
modification. 

• Vented top and bottom 
panels for cooling efficiency. 

• Rigid construction provides 
unlimited applications. 

CONSTRUCTION: 

The "DTE" Blank DeskTop Electronic Enclosures are designed to blend and complement 
today's modern computer equipment and can be used in both industrial and home. The 
end pieces are precision molded with an internal slot (all around) to accept both top and 
bottom panels. The panels are then fastened to V*" thick tabs inside the end pieces to 
provide maximum rigidity to the enclosure. For ease of equipment servicing, the rear/ 
bottom panel slides back on slotted tracks while the rest of the enclosure remains in- 
tact. Different panel widths may be used while maintaining a common profile outline. 
The molded end pieces can also be painted to match any panel color scheme. 





Enclosure 
Modol No. 


Panel 
Width 


PRICE 


I DTE-8 


8.00" 


$29.95 


DTE-11 


10.65" 


$32.95 


I DTE-14 


14.00" 


$34.95 



S10.00 Min. Order - U.S. Funds Only Spec Sheets - 25* 

Calif. Residents Add 6% Sales Tax 1980 Catalog Available- Send 41 i stamp 

Postage — Add 5% plus SI Insurance (if desired) 




ameco 



ELECTRONICS 



PHONE 

ORDERS 

WELCOME 

(415) 592-8097 



MAIL ORDER ELECTRONICS - WORLDWIDE 

1355 SHOREWAY ROAD. BELMONT, CA 94002 

PRICES SUBJECT TO CHANGE 




The Incredible 
Pennywhistle 103 

ylOtl.yS) Kit Only 

The Pannywhisllfl 103 is capable 3l recording data to and Irom audio tape without 

critical speed requirements lor !he recorder and il is able to communicate directly with 

another modern and tetminal lor telephone "hamming" and communications, in 

addition, rt is tree ol critical adjustmtntsand is built with n on -precis ion, readily available 

pan's. 

Data Transmission Method Frequency -Shift Keying, full-duplei (hall-duplex 

selectable). 

Maximum Data Rale 300 Baud. 

Data Format Asynchronous Serial (return to mafk level required 

between each character). 
Receive Channel Fraquanclat . . .2025 Hz lor space; 2225 Hz (or mart. 
Transmll Channel Fraquaneiet ..Switch selectable; Low (normal) =- 1070 space. 

1270 mark; High = 025 space. 2225 mart 

Receive Sensitivity - 46 dbm accoustically coupled. 

Transmit Laval -15 dbm nominal. Adjustable Irom -6 dbm 

to -20 dbm. 
Receive Frequency Tolerance ...Frequency reference automatically adjusts lo 

alow for operation between 1600 Hz and 2400 Hz. 
Digllal Data Interlace EIA RS-23ZC or 20 mA current loop (receiver is 

optoisolated and non-polar). 

Power Requirements 120 VAC. single phase. 10 Watts. 

Physical All eomponenls mourn on a single 5" by 9" 

printed circuit board All eomponenls included. 
Requires a VOM. Audio Osc illalor. Frequency Counter and/or Oscilloscope lo align 

TRS-80 
16K Conversion Kit 

Expand your 4K TRS-80 System to 16K. 
Kit comes complete with: 

* 8 each UPD416-1 (16K Dynamic Rams ) 250NS 

* Documentation for conversion 

T RS-16K $59.95 

JE610 ASCII 
Encoded Keyboard Kit 




The JEG10 ASCII Keyboard Kit can be interfaced into 
most any computer system. The kit comes complete 
with an industrial grade keyboard switch assembly 
(62-keys), IC's, sockets, connector, electronic compo- 
nents and a double-sided printed wiring board. The 
keyboard assembly requires +5V @ 150mA and -12V 
@ 10mA for operation. Features: 60 keys generate the 
full 128 characters, upper and lower case ASCII set. 
Fully buffered. Two user-define keys provided for 
custom applications. Caps lock for upper-case-only 
alpha characters. Utilizes a 2376 (40-pin) encoder 
read-only memory chip. Outputs directly compatible 
with TTL/DTL or MOS logic arrays. Easy interfacing 
with a 16-pin dip or 18-pin edge connector. 

JE610 (Case not included) S79.95 

Desk-Top Enclosure for 
JE610 ASCII Encoded Keyboard Kit 

Compact dusk-top enclosure: Color-Coordinated de- 
signer's case with light tan aluminum panels and molded 
end pieces in mocha brown. Includes mounting hardwere. 
Size: 3)4"H X 1454"W X 8K"D. 

DTE-AK $49.95 

SPECIAL: JE610/DTE-AK PURCHASED TOGETHER 

(Value $129.90) $124.95 

JE600 
Hexadecimal Encoder Kit 

FULL 6-BIT B BL 

LATCHED OUTPUT H OB 

19-KEY KEYBOARD V ■ HBW 

The JE600 Encoder Keyboard Kit provides two separate 
hexadecimal digits produced from sequential key entries 
to allow direct programming for 6-bit microprocessor 
or 8-bit memory circuits. Three additional keys are 
provided for user operations with one having a bistable 
output available. The outputs are latched and monitored 
with 9 LEO readouts. Also included tsa key entry strobe. 
Features: Full 8-bit latched output for microprocessor 
use. Three user-define keys with one being bistable 
operation. Debounce circuit provided for all 19 keys. 
9 LED readouts to verify entries. Easy interfacing with 
standard 16-pin IC connector. Only +5VDC required for 
operation. 

JE600 (Case not included) $59.95 

Desk-Top Enclosure for 
JE600 Hexadecimal Keyboard Kit 

Compact desk-top exclosure: Color-coordinated de- 
signer's case with light tan aluminum panels and molded 
end pieces in mocha brown. Includes mounting hardware. 
Size: 3!4"H x 8)4" W x 8M"D. 

DTE-HK $44.95 

SPECIAL: JE600/DTE-HK PURCHASED TOGETHER 
(Value $104.90) $99.95 > 



Circle 218 on inquiry card. 



BYTE August 1980 297 



tfUC A %M m Data 
OM.PI 9/mIVl Manager 



• CUSTOM DATA FILES 

• FAST/EASY/MENU DRIVEN 

• HELP COMMANDS 

• KEYED RANDOM ACCESS 

• MULTIPLE SEARCH KEYS 

• PRIVACY ACCESS CODES 

• WILD CARD SEARCH 



For 16K-32K PET, Dual Disk, and Printer 

FREE: LABEL PRINTER MODULE 
FREE: REPORT GENERATOR MODULE 
Specify CBM 2040 or COMPU/THINK 
Package $150 User's Guide only $25 

Introductory Demo Tape $5 Disk $ 8 

Check or Money Order plus $2 Shipping 

(NY residents add 8% Sales Tax) 

-DEALER INQUIRIES WELCOMED- 



JINI MICRO-SYSTEMS, Inc. 

P.O. Box 274-B • Bronx, NY 10463 



Circle 296 on inquiry card. 



X716's 

$19.95 

ANY QUANTITY 

$5 per order for shipping 
handling & insurance 



floppy drives 
$1550 

including two Siemens 8" 
drives, cabinet & power 



'intelligence Systems, Ltd. 

124 South Delaware. Indianapolis, IN 
(3I7) 63I-55I4 



Circle 299 on inquiry card. 



SCIENCE MATH STATISTICS 
ASTRONOMY MUSIC FINANCE 

Professionally written TRS-80' Software 

Star Finder $9.00 

Linear System Solver $14.00 

Curve Fitter $12.00 

Graphics Package $10.00 

Many Others. Free Catalog 

Budget Prices Fully Guaranteed 

BENCHMARK COMPUTING SERVICES 

P.O. Box 385, Providence Ut. 84332 

In Europe: 

Micro Gems 32 Buckingham Ave. 

Hucknall Nottingham 

NG15 SET England 



Master Charge 



Visa 



"TRS-80 is a trademark of 
Tandy Corporation 



NEED MASS STORAGE ? 
DUAL CASSETTE DRIVES 




> Cabinet enclosure and dual DEC TU-5S Cnssi>Ur> Drives 
wilh internal power supply- 

» The TU-58 is a random access, fixnd-lonrtih-block mass 
slof.-irje tape system storing 262 kilobytes ol dala with a 
variety ol applications. 

■ Interlace is EIA RS-422 balanced and RS 423 unbalanced 

■ Compatible with RS-232 C. 

» Optional relay iacfc mounting. 



P.O. Box 461 

Greene, New York 13778 

(607)656-4117 



G C 



ONTROLSinc 



-IE FLATS N Y 13841 



Circle 297 on inquiry card. 



PRINTER/CRT STAND 
FROM ^t3 STOCK! 




Sturdy 18 ga. "^ steel, painted 
black textured baked enamel. 

rear or bottom paper teed. 
26" wide x 18" deep x 26" high. 
Easily assembled with six bolts. 

CRT STAND: $90.00 

PRINTER STAND 
WITH PAPER TRAY: $99.00 

Please include payment with your order. 

Add tor cost ol 40 Lb. UPS charges, and 6% 
sales tax if shipment is to be made in Penna. 

AK INDUSTRIES, INC. 2727 Philmont Ave. 
Huntingdon Valley, Pa. 19006 

Dealer Inquiries Invited 



Circle 300 on inquiry card. 



CP/M— IBM 

Compatibility 

with 

REFORMATTED 

For $195 you can now transfer 
data between large and small 
systems. 

REFORMATTER", a Diskette Utility 
Program, enables you now to 
transfer textual data files in either 
direction between Z-80 or 8080 
based micros operating under 
CP/M and IBM systems using 
3741 diskettes. 

For detailed information contact 
MicroTech Exports 
912 Cowper Street 
Palo Alto, CA 94301 

TWX: 910-370-7457 MUH-ALTOS 

Dealer & OEM discounts available 



CASSETTE 
DUPLICATION 



TRS-80 (I & II), PET, APPLE, KIM, ATARI 

Quality software duplication is more 
than copying cassettes. Microsette du- 
plication uses a proprietary high speed 
duplicator designed specifically for 
computer program duplication. The fin- 
ished products are of consistent quality, 
guaranteed to load. Minimum order is 
100 with discounts for higher quanti- 
ties. Call (415) 968-1604 for details. 



«. 


M ..- 


• . 


s • ■■ • « 


:*9(< 


= •"•?. 


- • 


f .-*.*-,-.\ A P --- • 



MICROSETTE CO. 

475 Ellis Street 
Mt. View, CA 94043 



Circle 298 on inquiry card. 



MEMOREX 

Floppy Discs 

Lowest prices. WE WILL NOT 
BE UNDERSOLD!! Buy any 

quantity 1-1000. Visa Mastercharge 
accepted. Call free (800)235-4137 
for prices and information. All 
orders sent postage paid. 



PACIFIC 
EXCHANGES 

100 Foothill Blvd. 
San Luis Obispo. CA 
93401. (In Cat. call 
(805)543-1037.) 



Circle 301 on inquiry card. 




DISCOUNT PRICES 

NORTH STAR 

APPLE II 

MICROTEK 

ANADEX 

TRENDCOM 

CENTRONICS 

SOROC 

INTERTUBE 

THINKER TOYS 

SOLID STATE MUSIC 

& OTHERS 

Call for Prices 

(301) 694-8884 

FREDERICK COMPUTER 

PRODUCTS 

Municipal Airport 
Frederick, MD. 21701 



Circle 302 on inquiry card. 



Circle 303 on inquiry card. 



If North Star or Cromemco offer it . . . 

WE HAVE IT!! 

Immediate Delivery at Discount Prices 




NORTH STAR 
Horizon 2 

32K Double Density 

Assembled and Tested 
List $3095 

ONLY $261 9 



North Star KIT products have been 

discontinued. MiniMicroMart HAS 

INVENTORY of most items! 



KITS 




ASSEMBLED 


HORIZON 1 16K, DD . 


$1474 


HORIZON 1, DD $2279 


32K, DD, List $1999... 


. 1684 


32K, QD, List $2995 2539 


32K, QD, List $2199 . . . 


. 1869 


HORIZON 2, 32K, DD . $2619 


HORIZON 2, 16K, DD 


$1824 


32K, QD, List $3595 3049 


32K, DD, List $2399 . . . 


. 2034 


48K, DD, List $3590 3039 


32K.QD, List $2779... 


. 2359 


48K, QD, List $4090 3469 



64K, DD, List $3830 3239 

64K, QD, List $4330 3669 

NORTH STAR APPLICATIONS SOFTWARE 

Exclusive lor use with North Star Disk Systems — specify Double 
or Quad Density) 

MORTHWORD, List $399 $339 

WAILMANAGER, List $299 249 

NFOMANAGER, List $499 419 

3ENERALLEDGER, List $999 799 

\CCOUNTSRECEIVABLE, List $599 499 

4.CCOUNTSPAYABLE, List $599 499 

NORTH STAR HARD DISK HD-18 

18 megabytes, plugs into parallel port of North Star 
Horizon. Utilizes tried-and-proven 14" Century Data 
Vlarksman. List $4999. QUR pR|CE $41 gg 

NORTH STAR MDS-A - Double (or Quad) 
Density Disk System, Kit, List $799 . OUR PRICE $669 
Assembled and Tested, List $899 SPECIAL $719 

NORTH STAR MEMORY BOARDS 

I6K Dynamic RAM (RAM-16-A/A), Assembled, List $499 $420 

Kit, List $449 SPECIAL $299 

32K IRAM-32/A), Assembled, List $739 $620 

Kit, List $669 ONLY $499 




CROMEMCO 
System 3 

with 64K of RAM 
List $6990 

OUR PRICE 

$5890 



CROMEMCO SYSTEM 2 - Now features dual- 
sided drives — double the capacity. Similar to System 3, 
except features dual, double-sided mini floppy disk 
drives. List $3990 ONLY $3390 

Z-2 COMPUTER SYSTEM (can be rack 

mounted), List $995 $845 

SINGLE CARD COMPUTER - SCC-W 

4 MHz. List $450 $382 

NEW COLOR GRAPHICS INTERFACE - SDI 

List $595 OUR PRICE ONLY $505 

CROMEMCO HDD - 1 1 /22-megabyte Hard Disk 
for use with existing systems. DMA controller. Trans- 
fer rate of 5.6 megabytes/second. 

HDD-11, List $6995 OUR PRICE ONLY $5939 

HDD-22, List $11,995 $10,189 



CROMEMCO Z-2H 




Full 11 -megabyte Hard Disk 
system. FastZ-80A 
4 MHz processor, 
two floppy disk 
drives, 64K RAM 
memory, RS232 
special interface, 
printer interface, 
and extensive 
software available. 
List $9995 

our price $8489 



SHIPPING AND INSURANCE: Add $15 or Horizons, $2.50 for Boards and Software. Hard Disk Systems and Cromemco systems shipped freight collect. 
\dvertised prices are for prepaid orders. Credit card and C.O.D. 2% higher. Deposit may be required on C.O.D. All prices subject to change and offers 

subject to withdrawal without notice. . — -> 

- WRITE FOR FREE CATALOG - 



MiniMicroMart, Inc. 




master charge 



1618 James Street, Syracuse, NY 13203 (315)422-4467 TWX 710-541-0431 




Circle 305 on inquiry card. 



BYTE August 1980 299 



Computers, Disk System* 



SUPERBRAIN 

BvlNTERTEC 



INTERSYSTEMS 

formerly ITHACA AUDIO 




... - 

i.Jil 

32K or 64K (Double or Quad Density units 
available). Uses two Z-80 CPU's. Commercial- 
type terminal with 12" monitor. Dual double 
density minifloppies. Over 350 kilobytes of 
storage (twice that with quad density drives). 
Two serial RS232 ports, I/O ports standard. 
Expandable with optional S-100 S-100 inter- 
face. Comes with CP/M™ 2.2 operating sys- 
tem. MiniMicroMart includes BASIC inter- 
preter and can supply a wide range of CP/M 
Development and Application software. 

w/32K Double Density, List $2995 . $2685 

w/64K Double Density, List $3345 $2883 

w/64K Quad Density, List $3995 $3595 

W/64K Quad - MiniMicroMart 

Upgrade Special $3395 

MICROMATIOIM 




A 64K complete computer with dual density 
8" floppies (1 megabyte). Rack or vertical 
mounting. Systems with double-sided drives, 
hard disks, and multi-user (MP/M). 
Z+ 100 64K RAM, Computer, $2495. . $2099 
Z + 120 Includes two 8" disks, $4995 . . . $4199 
"Z" system features new distributed processing 
multi-user concept with one Z-80 per user, with 
Z-80 for MP/M (Master Satellite concept). 

AS LOW AS $11,899! 



SD SYSTEMS 

SDS-100, w/32K RAM, $6995 $5945 

SDS-200, List $8995 $7645 



RADIO 
SHACK 
TRS-80™ 

10% OFF! 





DPS-1, List $1795 

LIMITED TIME $1299* 

The new Series II CPU Board features a 4 MHz 
Z-80A CPU and a full-feature front panel. 20- 
slot actively terminated motherboard, with 25 
amp power supply (50/60 Hz operation, incl. 
68 cfm fan). 

COMPLETE SYSTEM with InterSystem 64K 
RAM, I/O Board w/priority interrupt and 
double density disk controller board. Full 1-year 
warranty, List $3595 

LIMITED TIME $2895* 

Above without disk controller, 

List $3195 LIMITED TIME $2539* 

* Prices good until September 15, 1980. 

HEWLETT-PACKARD 

HP-85A 

Desk-top computer - Call for PHce! 




MORROW 

THINKER TOYS® 
DISCUS M26™ 



26 megabytes of 
formatted storage 
List $4,995 



$4,199 




THINKER TOYS® 
DISK SYSTEMS 

Now includes CP/M® 2.2 
Discus 2D, List $1199 $1019 

Discus 2D, dual-drive, List $1994 $1694 

Discus 2 + 2, Assem., List $1549. ...... $1319 

Dual Discus 2 + 2, Assem., $2748 $2335 

All Morrow systems now include CP//W® 2. 2 

Circle 306 on inquiry card. 



NORTH STAR 

DOUBLE DENSITY 

CONTROLLER BOARDS 

Kit, List $399 *#»*%#% 

OUR PRICE $329 

Assembled and Tested, List $499 $399 

In Stock — First Time in 2 Years! 

FANTASTIC SAVINGS 

on a "QUAD" DENSITY 

HORIZON UPGRADE 

North Star Double Density Controller Board 
(see above) and a quad density MPI-52 (fea- 
tures superior disk handling and door mechan- 
ism. 



MDS-H-MQ/K Kit form 
List $999 



OUR PRICE 



$699 



MDS-H-MQ/A Assembled form, List $1099 

$759 
Shipping and insurance: Add $6. 



NORTH STAR MDS A 
Double Density Mini 
Floppy Disk System 

Double Density, Kit 

List $799 OUR PRICE $669 

Assembled and Tested $719 

Quad Version, Kit, List $836 

Assembled, List $1099 $896 

Above MDS-A units do not include cabinet or 

power supply. 

Shipping and Insurance: Add $7.50. 



Super Special! 

North Star 

Controller Board, 

Drive, Cabinet, ^"7/^Q 

and Power Supply V # w w 

Complete system similar to above but also 
includes a cabinet and an assembled/tested 
power supply for the drive (silver finish). Your 
choice of Shugart SA-400 or MPI-51 Double 
Density Drive or MPI-52 quad density drive 
(MPI drives feature improved door and disk 
handling mechanism). 

w/Controller Bd. kit, SA-400 $709 

w/Controller Bd. kit, MPI-51 $709 

w/Controller Bd. kit, MPI-52 $809 

w/Assembled Bd. and SA-400 $769 

w/Assembled Bd. and MPI-51 $769 

w/Assembled Bd. and MPI-52 $869 

Shipping and Insurance: Add $6. 

For converting existing Horizon 2 to quad, 

order additional MPI-52 

MPI-52 Quad Density Drive $379 



Terminals and Printers! 



TELEVIDEO TVI-912C 



SOROC 



TI-810 




IQ-120 

List $995 

SPECIAL 

$729 




IQ-140 List $1495 
SPECIAL $1149 



HAZELTIIME 



TI-810 Basic Unit, $1895 . ONLY $1695 
TI-810 w/full ASCII (Lower case), vertical 

forms control, and compressed print . $1895 
TI-745 Complete printing terminal 
with acoustic coupler, List $1695 .... $1399 



Upper and lower case, 15 baud rates: 75 to 
19,000 baud, dual intensity, 24 x 80 character 
display, 12 x 10 resolution. Numeric pad. Pro- 
grammable reversfble video, auxiliary port, 
self-test mode, protect mode, block mode, 
tabbing, addressable cursor. Microprocessor 
controlled, programmable underline, line and 
character insert/delete. "C" version features 
typewriter-style keyboard. List $950 

OUR PRICE $789 

920C (with 11 function keys, 6 edit keys and 
2 transmission mode keys, List $1030 

ONLY $849 

Intertec 

EMULATOR 

Software compatible with a Soroc IQ-120, 
Hazeltine 1500, ADM-3A or DEC VT-52. Fea- 
tures block mode transmission and printer port; 
12" anti-glare screen; 18-key numeric keypad; 
full cursor control. List $895 jk^*%#» 

OUR PRICE $729 





Intertec ||\|TERTUBE II 

List $995 ONLY $799 
12" display, 24 x 80 format, 18-key numeric 
keypad, 128 upper/lower case ASCII charac- 
ters. Reverse video, blinking, complete cursor 
addressing and control. Special user-defined 
control function keys, protected and unpro- 
tected fields. Line insert/delete and character 
insert/delete editing, eleven special line draw- 
ing symbols. 



1500 
ONLY 

$879 



1410 w/numeric keypad, List $900 $749 

1420 w/lower case and numeric pad 849 

1510, List $1395 1089 

1520, List $1650 1389 

BANTAM 550 

From Perkin-Elmer 

ONLY 

$799 

with 

anti-glare 

CRT 

ONLY $829 



CENTRONICS 

PRINTERS 

NEW 730, parallel, friction, tractor . . . $679 

NEW 737 parallel, friction, tractor $849 

779-2 w /tractor (same as TRS-80 Line 

Printer I), List $1350 1049 

702 120 cps, bi-direct., tractor, VFU 1995 

703 185 cps, bi-direct., tractor, VFU 2395 

704 RS232 serial version of 703, $2350 . . $1995 



PAPER TIGER 




IDS-440 Paper Tiger, List $995 . $895 
w/graphics option, incl. buffer, $1194 . . $989 
TRS-80 cable 45 



NEC SPINWRITER 



TM 





Terminal /Keyboard as well as 

RO Printer Only models available. 

CALL FOR PRICES! 

OKI DATA „ M 

Microline 80 only $649 

Tractor Feed Option $99 

Serial interface $89 

AXIOM IMP I $699 

COMPRINT 912 w/parallel interf. $559 
912 w/serial interface, List $699 $589 

MICROTEK, List $750 $675 

ANADEX 80-Col. Dot Matrix $849 



Above prices reflect a 2% cash discount (order prepaid prior to shipment). Add 2% to prices for credit 
card orders, C.O.D.'s, etc. Prices are f.o.b. shipping point. Prices are subject to change and offers 
subject to withdrawal without notice. WRITE FOR FREE CATALOG. circ|e 307 Qn inqujry oard 



MiniMicroMart, Inc. 

1618 James Street, Syracuse NY 13203 (315) 422-4467 TWX 710-541-0431 



VISA 



Unclassified Ac5s 



UNCLASSIFIED POLICY: Readers who are soliciting or giving advice, or who have equipment to buy, sell 
or swap should send in a clearly typed notice to that effect. To be considered for publication, an advertisement 
must be clearly noncommercial, typed double spaced on plain white paper, contain 75 words or less, and include 
complete name and address information. 

These notices are free of charge and will be printed one time only on a space available basis. Notices can be ac- 
cepted from individuals or bona fide computer users clubs only. We can engage in no correspondence on these 
and your confirmation of placement is appearance in an issue of BYTE. 

Please note that it may take three or four months for an ad to appear in the magazine. 



FOR SALE: New Glulion Rustrack inkless strip-chart 
recorder with paper roll. Also, Graphic Sciences Dex 570 
and Dex I graphic communications systems. They send 
photos and legal documents over phones, self- 
contained. R Quails, College Inn Apts, Box 238, Durant 
OK 74701, (405) 924-6306 after 5. 



FOR SALE: Heath H11A computer system with 64 K 
bytes memory. Uses DEC LSI-11/2 processor board. In- 
cludes serial input/output (I/O) board, all manuals, and 
documentation. System value over $2900. Will sell for 
$2500 or best offer. Art Lundquist, 13118 Glasgow Way, 
Ft Washington MD 20022, (301) 868-0005. 



FOR SALE: H8 computer with 24 K Godbout program- 
mable memory plus serial input/output (I/O) and 
cassette interface. AM assembled and tested and in- 
cludes recent version of Benton Harbor BASIC. All for 
$700 plus shipping. Daniel Bush, (404) 394-3341. 



WANTED: A used terminal printer with acoustic coupler, 
Bell System 103 compatible, and 300 bps. Also, need a 
video display terminal. J A Gatlin, 1115 S Main, Ottawa 
KS 66067. 



WANTED: BYTE magazines, February 1976 and June 
1976. T Higbee, 4572 Trafalgar Dr, La Palma CA 90623. 



FOR SALE: Expandor Black Box printer, 80-column for 
parallel port; $350. SwTPC MP-N calculator; $35, 
Newtech Model 68 music board and software; $48, 
SwTPC CT-64 terminal with CT-VM; $350. All postpaid. 
Dennis Doonan, 2307 Carlisle Ave, Racine Wl 53404. 



FOR SALE: Two teletypewriters. Friden 7102 with upper 
and lowercase, full ASCII, 110 baud RS-232/20 mA, 
paper-tape reader/punch, and wide carriage. $420 each 
or $800 for both plus freight. Gary, (317) 784-9519. 



FOR SALE: TRS-80 quick printer and/or line printer and 
cables. Both almost new. Stanley Strauss, (201) 
763-7249. 



FOR SALE: Three 8 K DRC S-100 programmable 
memories; one 8 K Seals S-100 programmable memory. 
$125 each. Perry A Lipford, 5005 Oxford Ave, Mays Land- 
ing NJ 08330, (609) 653-1542. 



FOR SALE: HP-67 programmable calculator. With stan- 
dard accessories, stat, math, standard, and business 
decisions PAC. Package of blank cards. Must sell. 
Recently purchased Apple II system. Will ship to first 
cashier's check or money order for $525. I pay shipping. 
100% operational. D Robbins, 1161 York Ave 1L, New 
York NY 10021. 



FOR SALE: Complete collection of BYTE. Both bound 
editions and single copies in good condition. Outstand- 
ing investment in personal computing. Make best offer. 
M N Andersen, 10684 Esmeraldas Dr, San Diego CA 
92124. 



FOR SALE: BYTE from February 1978 thru February 
1980. Available individually or in groups at $2 apiece. 
Also, first four issues of onComputing magazine for $8 
and February 1979 thru January 1980 Creative Computing 
for $20. Will answer all inquiries. John Scholze, Rt 5. Box 
449, Black River Falls Wl 54615. 



FOR SALE: RCA 1802 Cosmac processor with 16 K 
static memory, Netronics giant board, ASCII keyboard, 
Netronics video-display board, Netronics Level III 
BASIC, 5-card bus, power supply, Tiny BASIC, 15-inch 
GBC monitor, game cassettes, complete data, and in- 
structions. Everything in good working order. Original 
cost over $1000, asking $600. William Gordon, 1 1 Canter- 
bury Ln, Short Hills NJ 07078, (201) 467-9792. 



FOR SALE: Altair 8800A, 16 K, Meca Alpha I tape, 2 SIO, 
Act I terminal, 8 K, and Extended BASIC. $1400 takes 
all, or will separate. D Gietzen, 313 Meadow Ln, 
Hastings Ml 49058, (616) 945-5334. 



FOR SALE: 48 K Apple II with manuals, paddles, and 
software on cassette. Software includes the S-C 
Assembler II, an implementation of the FORTH 
language, and the Apple Invaders game. $1100 or best 
offer. Will ship via UPS. Tim Tillson, 2712 Adobe Dr, Fort 
Collins CO 80525, (303) 223-7364. 



PASCAL 

FROM START TO FINISH 



The BYTE Book of Pascal 

Edited by 
Blaise W. Liffick 

Based on the growing popularity of 
Pascal as a programming language, 
numerous articles, language forums and 
letters from past issues of BYTE 
magazine have been compiled to provide 
this general introduction to Pascal. In 
addition, this book contains several 
important pieces of software including 
two versions of a Pascal compiler - one 
written in BASIC and the other in 8080 
assembly language; a p-code interpreter 
written in both Pascal and 8080 
assembly languages; a chess playing pro- 
gram; and an APL interpreter written in 
Pascal. $25.00 Hardcover pp. 342 
ISBN 0-07-037823-1 



Beginner's Guide for the 
UCSD Pascal System 

by Kenneth L. Bowles 
Written by the originator of the UCSD 
Pascal System, this highly informative 
book is designed as an orientation guide 
for learning to use the UCSD Pascal 



System. For the novice, this book steps 
through the System bringing the user to 
a sophisticated level of expertise. Once 
familiar with the System, you will find 
the guide an invaluable reference tool 
for creating advanced applications. This 
book features tutorial examples of pro- 
gramming tasks in the form of self-study 
quiz programs. 

The UCSD Pascal Software Systems, 
available from SofTech Microsystems 
Inc, 9494 Black Mountain Road, San 
Diego CA 92126, is a complete general 
purpose software package for users of 
microcomputers and minicomputers. 
The package offers several interesting 
features including: 



• Programs which may be run without 
alteration on the General Automa- 
tion or DEC PDP-11 minicomputers, 
or on an 8080, 8085, Z80, 6502, 
6800, or 9900 based microcomputers. 

• Ease of use on a small, single-user 
computer with display screen and 
one or more floppy disk drives. 

• A powerful Pascal compiler which 
supports interactive applications, 
strings, direct access disks, and 
separately compiled modules. 

• A complete collection of develop- 
ment software: operating system, file 
handler, screen oriented text editor, 
link editor, etc. 

$11.95 ISBN 0-07-006745-7 



Please send 

D _ 



. copies of Beginner's Guide for the UCSD Pascal System 
. copies of The BYTE Book of Pascal 



Name 



Title 



Company 



Street 



City 



State/Province 



Code 



□ Check enclosed in the amount of $_ 

□ Bill Visa □ Bill Master Charge 

Card No. 



. Exp. Date_ 



iUTE 

.BuWrVS. 



Add 60c per book to cover postage and handling. 
70 Main Street, Peterborough, NH 03458 



HI 



B8 



302 August 1980 © BYTE Publications Inc 



FOR SALE: BYTE magazines: November 1976 and 
November 1977 thru June 1979. All twenty-one issues for 
$53. 1 pay postage. Send certified check or money order. 
David McCracken, 6850 Freedom Blvd. Aptos CA 95003, 
(408) 688-0358. 



FOR SALE: Dynamic programmable memory circuits. 
National MM5280-055 (2107) 4 K by 1. These parts are 
available due to project cancellation. They are new and 
guaranteed to meet specifications. Have 300; will sell all 
or part at $1.75 each.Doryn Johnson, 12A Triads, Logan 
UT 84321, (801) 752-9378. 



FOR SALE: Wang advanced programming calculator. 
Model 720B with Model 702 plotting output writer. Also, 
manuals and service schematics. $950. Frank Shea, 78 
Pilgrim Ave, Worcester MA 01604, (617) 798-8485. 



FOR SALE: 8800B Altair S-100 mainframe; $650, SSM 
video V8-1B graphics board; $95, two Godbout 8 K 
Econoram memory boards; $95 each, Altair 88ACR 
cassette-interface board; $85. Documentation included 
with each item. Robert Faulkner, 607 Bryan Ct, 
Altamonte Springs FL 32701, (305) 830-4387 after 7 PM. 



FOR SALE: Litton Model 1252 business computer in ex- 
cellent condition. Includes central processor Model 
1601, keyboard, printer (30 cps), punch, reader, and aux- 
iliary storage. Recently serviced. Computer comes com- 
plete with operator's manual and software for many 
business applications. $3000. Jesse Collum, (919) 
847-4053 or (919)556-4031. 



FOR SALE: Processor Technology 64KRA-1 (64 K by 8) 
memory board for S-100 computers with 2 MHz clock 
such as SOL-20, IMSAI 8080 and 8085, and Altair, Has 
three different bank select options; includes manual 
with updates, $575. John Edwards, 408 13th St #545, 
Oakland CA 94612, (415) 462-3394. 



FOR SALE: Ohio Scientific Challenger II-8P cassette- 
based system with 20 K bytes static memory, 540 video 
board, 542 polled keyboard, two full parallel ports, OSI 
Assembler/Editor, some game tapes, and two binders of 
documentation and notes. This is a plain but reliable 
computer with a heavy power supply. Cost about $1250 
new; will sell for $650 or best offer. Gregg Williams, (603) 
924-9281 Monday thru Thursday. 



FOR SALE: Ohio Scientific printed-circuit boards, 
documentation, backplane, and cabinet for 6800 or 6502 
Challenger system. Original cost $300, will sell for $200. 
Included are: #400 processor and input/output (I/O) 
board, #420 4 K programmable memory boards, #430 
cassette A/D and D/A board, #440 Video Graphics board, 
#450 8 K read-only memory and I/O board, and #480 
backplane board. Paul Manos, 28743 Lincoln Rd, Bay 
Village OH 44140, (216) 331-3010 evenings. 



FOR SALE: Memorex hard-copy terminal with digital 
cassette. 60 characters per second. Includes all 
manuals. Needs some work. $500. Michael C Lewis, 
1602 Shepherd Dr, Duarte CA 91010. 



WANTED: Clock generator circuit for TMS9900 
microprocessor (ie: TIM9904 or 74LS362). Please contact 
me if you can sell me one or know of a source for one. I 
am also interested in corresponding with other 9900 
users. Andy Hall, 4124-55th St, Des Moines IA 50310, 
(515)276-2459. 



FOR SALE: Sphere 6800 computer, 12 K memory, video 
board, cassette/modem interface board. Best offer over 
$300; original cost $1000. David Moore, 1518 Jefferson, 
Quincy IL 62301, (217) 228-1792. 



FOR SALE: DECwriter II with APL option, current loop 
and RS-232, writing table, noise shield. Complete with 
maintenance manual and all schematics. Maintained by 
DEC and in perfect working order. Reliable hard copy at 
30 cps in full ASCII or APL character sets. Character set 
software-selectable. Asking $1800. Lloyd Botway, 325 
Dartmouth Rd, Kansas City MO 64113, (816) 361-4968. 



WANTED: Printer (and/or Micromodem II, Disk II without 
controller) for Apple II. Will trade (or sell) Acoustat X 
direct-drive electrostatic speaker system and Kenwood 
KT8300 FM/AM tuner. Also, Applesoft read-only-memory 
card without Autostart read-only memory for sale; make 
offer. Charles White, 1712F Newport Cir, Santa Ana CA 
92705, (714) 979-9666 days, (714) 751-1296 evenings and 
weekends. 



FOR SALE: BYTE from first issue up to current. All 
original publications in excellent condition. No marks, 
scribbles, or underlines. Give issues you want and offer. 
C Tseng, 67-05 Austin St, Forest Hills NY 11375. 



BOMB 




BYTE 


sC 


ingoing Monitor Box 


Article # 


Page 


Article Author 


1 


22 


A Build-lt-Yourself Modem for Under 

$50 Ciarcia 


2 


58 


The Hard-Disk Explosion: High- 
Powered Storage for Your Personal 
Computer Manuel 


3 


76 


The Evolution of FORTH, an Unusual 
Language Moore 


4 


100 


What Is FORTH? A Tutorial Introduc- 
tion James 


5 


150 


BREAKFORTH Into FORTH Miller and 

Miller 


6 


164 


FORTH Extensibility: How to Write a 

Compiler in Twenty-Five Words or 

Less Harris 


7 


198 


Khachiyan's Algorithm, Part 1: A New 
Solution to Linear Programming 
Problems Berresford, 

et al 


8 


210 


Construction of a Fourth-Generation 

Video Terminal, Part 1 Wierenga 



FOR SALE: Three 16 K dynamic S-100 memory boards 
($75 each); minicomputer system PDP-8/L 4 K memory; 
four cartridge drives; ASR33; 100 cps printer; and RS-232 
interface. Cost of entire system, $750. Kalon Kelley, 149 
Rametto Rd, Santa Barbara CA 93108, (805) 969-1539. 



WANTED: PDP-8/E minicomputer or MM8-EJ extended 
memory option for same. Name your price. Martin J Dur- 
bin, 2649 N Sacramento, Chicago IL 60647, (312) 
235-1620 evenings. 



FOR SALE: Memorex 651 floppy-disk drive (new), thirty 
blank disks, Ken Welles floppy-controller board; all for 
$350. 2708s $5 each, 5204s $4 each, 1702s $3 each, 
4116s $5 each. Paper-tape reader; $10. Gordon Wilson, 
819 San Lucas Ave, Mtn View CA 94043. 



FOR SALE: D C Hayes Micromodem for Apple II. Like 
new, works perfectly. Only $320. H Rothman, 218 Hun- 
tington Rd, Bridgeport CT 06608, (203) 579-0472. 



WANTED: Processor Technology VDM-1 board, working 
or not, and ALS-8 information. Richard Miller, POB 6337, 
Jacksonville FL 32205. 



WANTED: Heathkit ET-3400 microprocessor trainer only 
in kit or assembled; also, Radio Shack TRS-80 Level II 
with 16 K, integral keyboard, power supply, video 
monitor, and cassette recorder. All in good condition. 
Roland Dumont, 731 Jacques Berthiaume, Ste-Foy 
Quebec, G1V 3T2 Canada. 



FOR SALE: Chalco high-speed paper-tape reader; 5, 6, 7, 
or 8 level tape (ASCII or Baudot), 625 cps, self-contained 
power supply, simple interface. Industrial quality, ex- 
cellent condition, complete with documentation. New; 
S755. Asking $100. Fred Goldberg, 29 Clearview Rd, E 
Brunswick NJ 08816, (609) 734-2160 days. 



WANTED: Schematics (service documentation) for 
Vogue Instrument Co line printer. Please call Steve 
Gardner, Birmingham AL 35209, (205) 942-8567. 



FOR SALE: New P4 video display; $30. Purchased from 
Electrolabs; never used. Will ship UPS COD. Frank 
Sneade, Rt 1 Box 60A, Rawlings VA 23876, (804) 
949-7835. 



FOR SALE: SIM-1 microcomputer with Microsoft BASIC 
(read-only memory), 4 K monitor, 1 K programmable 
memory, and power supply. All manuals and documen- 
tation supplied. Will ship UPS for $250. Robert Dixon, Rt 
1 Box 239-A, Lynnville TN 38472, (615) 363-7489. 



May BOMB Results 
Floppy Disks 

BYTE readers output their 
interest in Steve Ciarcia's "I/O 
Expansion for the Radio Shack 
TRS-80" (page 22) by expand- 
ing Steve's rank with another 
first place. John Hoeppner also 
interfaced well with readers, 
receiving a second place for 
his floppy-disk-controller 
article (page 72). First place for 
May was 1.84 standard devia- 
tions above the mean, while 
second was 1.09, closely 
followed by Gregory J Walker 
("Error Checking and Correct- 
ing for your Computer," page 
250) in third place and Emory 
Cook ("The Cassette Lives 
On," page 12) in fourth place. 



August 1980 © BYTE Publications Inc 303 



Reader 
Service 



To get further information on the products advertising in BYTE, fill out the reader service card until you 
name and address. Then circle the appropriate numbers for the advertisers you select from the list. Add a 
15-cent stamp to the card, then drop it in the mail. Not only do you gain information, but our advertisers are 
encouraged to use the marketplace provided by BYTE. This helps us bring you a bigger BYTE. "Correspond 
directly with company. 



Inquiry No. Page No. 



Inquiry No. Page No. 



Inquiry No. Page No. 



Inquiry No. Page No. 



240 
206 
263 
225 
174 
300 

94 
271 

74 
106 

247 
160 
139 
7 
35 



10 
294 



25 
27 
171 
253 
137 
302 

287 

145 



163 

14 

204 

221 

135 

169 

211 

212 

64 

134 

8 

70 

245 

288 
140 
312 
69 
264 
215 
277 

278 
257 

32 
249 
165 

12 
250 

242 

1 



199 
237 

209 
173 
239 
258 

243 
58 
113 

50 
138 
91 



AB Computers 278 

Ackerman Digital 245 

Addison-Wesley Publ. Co. 288 

Adv Computer Prod 270, 271 

AEl 227 

AK Industries 298 

Altos 136, 137 

Alpha Products Co 290 

American Square Comp 116 

Ancon/Forth Generation 

Software 157 

Ancrona 282 

Anderson Jacobson 219 

Apparat 179 

Apple Computer 12, 13 

Applied Digital Data 

Sys (ADDS) 55 

Applied Logic Inc. 290 

Arkansas Systems Inc. 223 

Artec Electronics 16 

ASAP 295 

ATV Research 276 

Automated Equipment Inc 

(AEl) 227 

Axiom 41 

base 2 Inc 45 

Basic Magazine 225 

Beckian Enterprises 286 

John Bell Engineering 192 

Benchmark Computer 

Services 298 

Beta Business Systems Inc 294 

Beta Comp Devices 36 

Bower-Stewart & Associates 202 

BYTE Books 140,213,302 

BYTE Back Issues 247 

BYTE Subscription 246 

C & S Electronics 221 

California Comp Sys 20, 21 

California Data Corp 244 

California Digital 266 

Cambridge Dev Labs 190 

Cambridge Dev Labs 225 

Cap'n Software 247 

Cap'n Software 247 

Central Data 101 

CFR Assoc Inc 190 

Chrislin Industries 14 

Chrislin Industries 110 

Cleveland Consumer Computers 

& Components 281 

Code Construction Co 294 

COLOR Software 194 

CompuMart 245 

CompuServe (MicroNET) 107 

ComputerCity 289 

Computer Components Inc 255 

Computer Distributors 292 

Computer Factory 115 

Computer Forms 292 

Computer Shopper 288 

Computer Specialties 52 

Computer Specialties 284 

Computers Wholesale 222 

CompuView 18 

Concord Computer 

Components 284 

The CPU Shop 279 

Cromemco 1, 2 

Cybernetics Inc 229 

Dal-Comp 293 

Darrell's Appleware 157 

DAR Sales 292 

Data Discount Center 151 

Datadisk Systems 243 

Data Prod Maintenance 

Corp 276 

Datasmith 246 

Datasoft 227 

Delta Products 277 

Designers & Builders 

Information Service (DBIS) 288 

DG Electronics 280 

Diablo (Div of Xerox) 89 

Digital Arts Group Contract 

Services 168 

Digital Marketing 74 

Digital Graphic Systems 192 

Digital Pathways 133 



248 Digital Research Comp (TX) 283 

78 Digital Research Corp (CA) 121 

161 Discount Software Group 220 

162 Disk/3 Mart Inc 221 

179 Dual Systems Control Corp 230 

164 DWS Marketing Int'l 221 

96 Dynacomp Inc 147 
132 Ecosoft 188 

72 ELCOMP Publ Inc 112 
223 Electrolabs 268, 269 

156 Electronic Control Tech 217 

217 Electronic Systems 259, 260, 261 

73 Electronic Sys Furniture Co 114 

281 Engineering Analysis 
Software 292 

105 Essex Publishing 156 

205 Excom 245 

182 Executive Business Sys 233 

190 Faircom 239 

232 Faragher & Assoc 276 

213 Farnsworth Computer 247 

290 Feith Software 294 

282 Field Service Search 292 

* Five Stones Software 229 

76 FMG Corp 118 
55 Forth Inc 85 

" Frederick Computer Prods 298 

297 G C Controls 298 

29 General Business Computer 4B 

268 Gimix 290 

127 Godbout Electronics 181 

109 Mark Gordon Computers 165 

20 Graham Dorian 35 

168 GW Computers 223 

142 H & E Computronics 195 

4 Hardhat Software 8 

188 Hardside 237 
279 Harrex Corp 292 

130 Hayden Book Co 187 

3 Heath Company 6 

11 Heath Company 17 

37 Heath Company 57 
26 Hewlett-Packard 43 

48 High Technology Inc 72 

251 Hobbyworld Electronics 285 

42 Houston Instruments 65 

216 Houston Instruments 65 

267 infinite Inc 290 

129 Information Unltd Software 185 

39 Industrial Micro Sys 61 

189 Inmac 239 

38 Integral Data 59 
118 Integrand 172 

299 Intelligence Sys Ltd 298 

292 Interface Inc 294 

16 Intertec Data Sys 25 

31 Intertec Data Sys 51 

* Ithaca Intersystems 9 
46 Ithaca Intersystems 70 

272 J & S Software 290 

220 Jade Comp Prod 264, 265 

218 Jameco Electronics 296, 297 
262 Keith Jenkins & Assoc Inc 288 
236 Jepsan Group K Inc 276 

296 Jini Microsystems 298 

61 Kemco Ltd 93 

66 Kenyon Micro Systems 104 

86 Robert Kleven & Company 128 

77 Konan Corp 119 

289 Larwin/Livers Assoc Inc 294 

* Lifeboat 44, 108, 109 
266 The Lisp Co 290 

121 Lobo Drives Int'l 175 

154 Lomas Data Products 217 

88 Macrotronics 130 

63 Malibu Electronics 99 

111 Marketllne 168 

123 Marymac Industries 178 

92 Matchless Systems 134 

* Meas Sys & Controls 29, 147, 
157, 165, 177 

97 MICAH 147 
281 Mlcops Inc 292 

99 Mlcroamerica Distributing 148 

146 Micro Ap 203 

196 Micro Appl Grp (MAG) 241 

197 Micro Appl Grp MAG) 241 
274 Micro Business World 291 
114 Microbyte Software 168 



53 Micro Computer Brokers 80 

■ Micro Computer Discount 244 

89 Microcomputer Tech Inc 131 
125 Microcomputer Tech Inc 179 

157 MicroDaSys 218 

52 Micro Data Base Sys 77 

181 Micromail 232 

87 Micro Management Sys 129 

• Micropolis 162, 163 

• Micro Pro Int'l 105 
298 Microsette 298 

62 Microsoft 97 

30 Microsoft (Cons Prod Div) 49 

303 Microtech Exports 29B 

28 Microtek Inc 47 

84 The Micro Works 126 
57 Micro World 87 

• Mighty Micros 120 
241 Mikos 278 

103 Miller Microcomputer Serv 154 
155 Mini Computer Suppliers 217 

305 Mini Micro Mart 299 

306 Mini Micro Mart 300 

307 Mini Micro Mart 301 
207 Miro Computers Inc 245 

147 Mittendorr Engineering 204 
15 Morrow/Thinker Toys 23 

33 Morrow/Thinker Toys 53 

13 Mountain Hardware 19 

152 Mountain Hardware 210 

65 mpi 103 

259 MTI 288 

144 MT Microsystems 199 

256 Multi Business Comp Sys 288 

54 MVT Microcomputer Sys 83 

' The National Comp Shows 111 

95 National Small Comp Show 141 

131 Nautilis Systems 188 

98 NEECO 148 

100 NEECO 149 

41 Netronics 64 

82 Netronics 125 

83 Netronics 125 

176 New England Business Service 
(NEBS) 228 

■ Noble Computer Corp 292 

• Northern Tech Books 207 

17 North Star 27 

270 Northwest Comp Services 290 

148 Nycom Inc 206 

310 Ohio Scientific InstrCV IV 

51 Okidata Corp 75 

19 OK Machine & Tool 33 

184 Oliver Advanced 
Engineering 235 

90 Omega Research 132 

104 Omega Sales Co 155 
186 Omikron 235 

' OnComputing 113 

44 Orange Micro 68 

45 Oregon Software 69 

143 Osborne/McGraw-Hill 197 

158 OSM Computer Corp 219 

' Owens Associates 144, 145 

235 Pacific Exchanges 276 

301 Pacific Exchanges 298 

222 Page Digital 267 

244 Pan American Elec 280 

(A Radio Shack Auth Sales Ctr) 

192 PCD Systems Inc 240 

9 Percom Data 15 

18 Percom Data 31 

81 Personal Computer Sys 124 

128 Personal Computing '80, 183 

233 Personal Progs by Victor 276 

85 Personal Software 127 

• Phase One Systems 209 
194 Pickles & Trout 241 

5 Power One Inc 10 

228 Priority One 273 

229 Priority One 274, 275 

214 Professional Data Sys 247 

286 Professional Management 

Services 294 

60 Professional Software Inc 91 

139 QC Micro Systems 193 

219 QT Comp Systems 262, 263 

150 Quality Software 208 

102 Quasar Data Products 153 



254 Quest 287 

230 Quintrex Inc 276 

36 Racet Computes 56 

68 RCA Solid State 106 

80 RCA Solid State 123 

269 Eric C Rehnke Tech Serv 290 

172 RNB Enterprises 226 

178 Robotics Age 229 

159 Rochester Data 219 

43 Rockwell Int'l Micro Sys 67 

170 S-100lnc225 

195 SC Digital 241 

191 SCDP 239 

2 Scion Corp 5 

198 Scifronics 242 

183 Scott Instruments 234 

24 SD Systems 39 

119 Seattle Comp Products 173 
166 Service Technologies 223 

23 Shepardson Microsystems 38 

203 Michael Shrayer Software 244 

• Shugart 7 

75 Sigma Int'l 117 

71 Sirius Systems 205 

116 Sirius Systems 171 

293 SMA 294 

49 Small Business Appl 73 

185 Small Sys Design 235 

21 Smoke Signal Broadcasting 37 

22 Smoke Signal Broadcasting 
(Dealers Only) 37 

193 Softech 201 

175 Software Concepts 227 

122 Software Development & 

Training 177 

187 The Software Exchange 236 

280 The Software Farm 292 

283 Software Labs 269 

112 Software Tech for Comp 

(STC) 168 

285 Software Tool Works 294 

208 The Software Works 246 

201 The SoHo Group 243 
227 Solid State Sales 258 
153 Sorcim 216 

200 Sorrento Valley Assoc 243 

79 Southern Computer Sys 122 

308 Southwest Tech Prod Corp CV II 

120 Spectrum Software 174 
6 SSM11 

136 Strategic Simulations 191 

110 Structured Systems Group 167 

115 Structured Systems Group 169 

177 SubLOGIC 253 

59 Summagraphics 90 

252 Sunny Int'l 286 

93 SuperSoft 135 

108 SuperSoft 165 

133 SuperSoft 189 

■ Synchro Sound 79, 184 

124 Synergetic Comp Prod 178 

107 Tarbefi Electronics 159 

234 TBI 276 

40 Tech Sys Consultants (TSC) 63 

141 Tec-Mar Inc 194 

180 Texas Instruments 231 

' Robert Tlnney Graphics 211 

202 TNW Corp 243 

260 Torrey Pines Busn Sys 288 

• Trionyx Electronics 172 
275 TYC Software 292 

273 Ucatan Computer Store 290 

309 United Business Prod CV III 

• United Software of America 95 
47 US Robotics 71 

• VAN DATA 180 

261 Videx 2B8 

224 Vista Computers 272 

246 VR Data 282 

226 Wameco 258 

34 The Warehouse 54 

' Whitesmith's Ltd 81 

255 Wintek Corp 288 

291 Wisconsin Area Komputer Co 
(WAKCO) 294 

231 Worldwide Electronics 276 
56 XCOMP, Inc 86 

210 Zs Systems 246 



304 August 1980 © BYTE Publications Inc 



A 



A COMPANY TO RELY ON. . . 
4 5 \ UNITED BUSINESS PRODUCTS 






Custq^p^grmts 
Wi^^^arantee 






<s-n^- 



..-■■ 



\ 







UNITED BUSINESS PRODUCTS 

20268 E. Carrey Rd. 
WALNUT, CA. 91789 



A 



United 
Business 
Products 



(213) 448-4850 
(714) 594-5966 



NAME OF COMPANY . 



ADDRESS 



CITY, STATE, ZIP 



ATTENTION OR DEPT. 



A O The swingline table top burster will separate single-ply continuous 
forms into individual sheets up to 15". Length 2W to 12". Paper weight 10 to 
110 lb. bond. Speed is constant at 125 ft. per minute. 

Wt. 95 ibs. Sale Price $879.00 

B □ Our custom forms have a guarantee that speaks for itself. Our time on 
forms range from two to five weeks for custom work and before we start a job 
we now give a guaranteed shipping date and price, depending on art work, 
from two to five weeks and for every day we're late we give you a 10% discount. 
To get a quote just mail the detached portion of this ad with sample of form or 
layout and we will call you the day we get the information with a price and 
guaranteed day of shipment. 

C □ The swingline table top decollator is a portable unit which separates 
both carbon and carbonless continuous computer forms into stacks. The 
separated carbon is easily and neatly removed from carbon pick-up spool. 
Form size is up to 15" wide. Wt. is 10 to 110 lb. bond paper, and the speed is 
variable from 75 to 200 feet per minute and takes only 120 volts AC 60 hertz to 
operate. 



Wt. 40 Ibs. 



Sale Price $369.00 



D □ The Datatech Intimus 007 shredder works for Scotland Yard, for 
government authorities, for important corporations, banks and embassies. 
The cutting capacity is 12 to 14 sheets at one pass. Cross cul is 1/35 x3/8. It has 
a 2 H.P. motor and runs off of 220/380 V 3 phase. 



Wt. 320 Lbs. 



Sale Price $6599.00 



E D The Intimus 306 is designed for trouble free operation and has a switch 
for forward and reverse rotation. It has 2 motors with terminal overload. 
Housing consists of coated steel, mounted on rubber cushions for noiseless 
shredding. The 306 can sit on a table or a stand. Cutting width is V&" or '/*" and 
has two 150 watt 1 10 V 60 cycle, 1 phase motors. 

Wt. 66 Lbs. Sale Price $1189.00 

F □ The Intimus Simplex is designed for security without problems in the 
office. One push of the button renders confidential information into five 
illegible paper strips Vo" thin. The simplex has a wide opening in the middle for 
throw away of cans, etc. Even a paper clip is simply cut into pieces. The cutting 
capacity is 8 to 10 sheets at one time. It has a 1/5 HP. motor and runs off of 110 
volts. 

Wt 27 Lbs. 



Sale Price $569.00 

G □ Our catalog consists of more information on equipment in this ad. 
Other models are available plus a complete line of calculators and typewriters 
by Adler. Lathem time recorders, several varieties of safes, and our 
disintegrator that destroys paper, aluminum, film and carbon to a complete 
loss of identity. 

Price $2.00 

H D Free Brochures and more information: 

1. □ Business Forms 

2. n Calculators 

3. d Forms Handling Equipment 

4. a Time Recorders 

5. Q Typewriters 



Terms: Check or money order U.S. funds only. Prepaid orders add 3% S/H, COD's add 5% S/H (U.S. only). California 

residents add 6% sales tax. 
Prices subject to change without notice. Sale ends Sept. 15, 1980 



Circle 309 on inquiry card. 



The home computer you thought was 
years away is here. , — ~* 



c «iuiiiib er op 




Ohio Scientific's top of the line personal com- 
puter, the C8P DF. This system incorporates 
the most advanced technology now available 
in standard configurations and add-on options. 
The C8P DF has full capabilities as a personal 
computer, a small business computer, a home 
monitoring security system and an advanced 
process controller. 

Personal Computer Features 

The C8P DF features ultra-fast program execu- 
tion. The standard model is twice as fast as 
other personal computers such as the Apple II 
and PET. The computer system is available 
with a Gf option which nearly doubles the 
speed again, making it comparable to high end 
mini-computer systems. High speed execution 
makes elaborate video animation possible as 
well as other I/O functions which until now, 
have not been possible. The C8P DF features 
Ohio Scientific's 32 x 64 character display with 
graphics and gaming elements for an effective 
resolution of 256 x 512 points and up to 16 
colors. Other features for personal use include 
a programmable tone generator from 200 to 
20KHz and an 8 bit companding digital to 
analog converter for music and voice output, 
2-8 axis joystick interfaces, and 2-10 key pad 
interfaces. Hundreds of personal applications, 
games and educational software packages are 
currently available for use with the C8P DF. 
Business Applications 
The C8P DF utilizes full size 8" floppy disks 
. and is compatible with Ohio Scientific's ad- 
vanced small business operating system, 
OS-65U and two types of information manage- 
ment systems, OS-MDMS and OS-DMS. 



The computer system comes standard with a 
high-speed printer interface and a modem in- 
terface. It feaiures a full 53-key ASCII 
keyboard as well as 2048 character display 
with upper and lower case for business and 
word processing applications. 
Home Control 

The C8P DF has the most advanced home 
monitoring and control capabilities ever 
offered in a computer system. It incorporates 
a real time clock and a unique FOREGROUND/ 
BACKGROUND operating system which allows 
the computer to function with normal BASIC 
programs at the same time it is monitoring 
external devices. The C8P DF comes standard 
with an AC remote control interface which 
allows it to control a wide range of AC appli- 
ances and lights remotely without wiring and 
an interface for home security systems which 
monitors fire, intrusion, car theft, water levels 
and freezer temperature, all without messy 
wiring. In addition, the C8P DF can accept 
Ohio Scientific's Votrax voice I/O board and/or 
Ohio Scientific's new universal telephone inter- 
face (UTI). The telephone interface connects 
the computer to any touch-tone or rotary dial 
telephone line. The computer system is able to 
answer calls, initiate calls and communicate 
via touch-tone signals, voice output or 300 
baud modem signals. It can accept and 
decode touch-tone signals, 300 baud modem 
signals and record incoming voice messages. 
These features collectively give the C8P DF 
capabilities to monitor and control home func- 
tions with almost human-like capabilities. 
Process Controller 

The C8P DF incorporates a real time clock, 
FOREGROUND/BACKGROUND operation and 
16 parallel I/O lines. Additionally a universal 

Circle 310 on inquiry card. 



accessory BUS connector is accessible at the 
back of the computer to plug in additional 48 
lines of parallel I/O and/or a complete analog 
signal I/O board with A/D and D/A and 
multiplexers. 

Clearly, the C8P DF beats all existing small 
computers in conventional specifications plus 
it has capabilities far beyond any other com- 
puter system on the market today. 
C8P DF is an 8-slot mainframe class computer 
with 32K static RAM, dual 8" floppies, and 
several open slots for expansion. 

C8P J 950 

Or get started with a C8P with cassette inter- 
face, 8K BASIC-in-ROM which includes most 
of the features of the C8P DF except the real 
time clock, 16 parallel I/O lines, home security 
interface and accessory BUS. It comes with 
8K static RAM and Ohio Scientific's ultra-fast 
8K BASIC-in-ROM. It can be expanded to a 
C8P DF later. Base price $950. Virtually all trie 
programs available on disk are also available 
for the C8P cassette system on audio 
cassette. 

Computers come with keyboards and floppies where speciiied. 
Other equipment shown is optional. 

For literature and the name of your local 
dealer, CALL 1-800-321-6850 TOLL FREE. 



1333 SOUTH CHILLICOTHE ROAD 
AURORA, OH 44202 • [21 6] 831 -5600